Does the world have to worry about a new wave of Muslim extremists who are inspired by al Qaeda but working alone?

British intelligence officials are treating Wednesday's brutal murder of an off-duty soldier on a London street as an act of terrorism by lone wolves. The suspects are believed to be Islamist extremists inspired by al Qaeda but with no formal ties to any organized group. Similarly, the Boston Marathon bombing suspects — the Tsarnaev brothers — were believed to have had contact with radical Islamists, but plotted the April attack on their own.

With al Qaeda's leadership and network severely weakened by more than a decade of war with the U.S. and its allies, do lone wolves now pose the greatest threat to Western cities?

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The U.K.'s intelligence service, MI5, has long feared that lone-wolf terrorists pose a major danger. And Tom Whitehead, security editor at Britain's Telegraph, notes that this danger is one that even experienced counter-terrorism experts are essentially powerless to stop. "The nature of the new threat is often such attacks can come out of nowhere," Whitehead says, "with no network or obvious plot for MI5 or the police to pick up on in advance."

The reason for that is that lone wolves don't do things intelligences services can spot, such as contacting known terrorists or visiting countries where al Qaeda has training camps. They simply get radicalized by jihadist internet sites and cook up their own plots, then strike without warning. Clive Irving says at The Daily Beast that it's possible the London attackers — who struck in broad daylight and then stuck around to declare war while witnesses videotaped them with cell phone cameras — was just a one-off. But, he said, it could also be the West's new worst nightmare.

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The two assailants could, indeed, just be a couple of deranged freelancers. But the guidance British ministers have been giving reporters assumes something much graver, a form of terrorism so unsophisticated and amateur that it can't be detected by existing surveillance methods.

The fact that the wild, bloodied harangue to camera was delivered by a black man with no trace of a foreign accent — indeed, in an accent that seemed to originate in south London in particular — suggests homegrown militants, perhaps men radicalized via the Internet, through a form of widely dispersed propaganda rather than targeted brainwashing. [The Daily Beast]

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The concern is that other people, other troubled young Muslim men, will see this, see the publicity it is getting, the impact it is having on the nation's leaders, and think: that works, that's the way to a horrible form of global celebrity, that's the way to get my face on the front pages. As far as I understand it, al Qaeda isn't really an organization any more, it's a sort of ideal. Any thuggish youth with internet access or even, it seems, a cleaver and a Ford Fiesta can commit an act of brutality and portray themselves as fighting for the Caliphate or trying to drive troops out of Afghanistan. [Telegraph]

We should redouble our efforts to ensure soldiers feel safe and valued; the notion that there are areas where they are abused or assaulted is repugnant. This attack was unprecedented in brazenness and savagery but London is too civilized a city to respond except with compassion and solidarity. [London Evening Standard]

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Czech police seek US man suspected of 4 murders

BRNO, Czech Republic (AP) — An American man is suspected of killing a family of four and is on the run in the Czech Republic and likely armed, officials said Thursday.

The bodies of the four victims — identified by neighbors as a married couple and their two sons — were found by firefighters who came tackle a fire in a house in Brno, the country's second-largest city.

Firefighters spokesman Jaroslav Mikoska said rescuers immediately realized that "a violent crime had likely been committed there." The fire did not badly damage the house.

Brno Police spokeswoman Petra Vedrova identified the suspect as Kevin Dahlgren, born in 1992, and released his photograph. A Facebook page showing the same photograph says that Dahlgren is from Palo Alto, California, and lives in Brno.

Vedrova said that all four victims were related. A Czech public television reported that Dahlgren was the nephew of the parents. Police did not immediately confirm that relationship.

A local band, Ukulele Orchestra jako Brno, confirmed to The Associated Press that two of its members were among the victims, but declined to comment further. Dahlgren's Facebook page contained a link to the band.

Vedrova and neighbors said Dahlgren had only been in Brno for a few weeks.

"As far as we know he came for a visit," neighbor Ivana Pohankova told the AP.

"Such a tragedy, they were so young," Pohankova said. She said one son was 24 and the other was a teenager under 18.

"We didn't hear anything but a neighbor came to say there was a smoke coming from the house. That's how they discovered it."

Police asked the public for help finding Dahlgren, but warned that he might be dangerous and likely has a gun. They did not immediately release any other details about the suspect or about the killings.

Another neighbor told the Czech public broadcaster he met Dahlgren two days ago and he invited him for a beer.

"He looked absolutely fine and kept smiling," Jan Fiala said. "He said he didn't like the western world, that life in America is too fast while people here are more placid."

Brno is located 200 kilometers (125 miles) southeast of Prague. Police say they cooperated with international law enforcement agencies to confirm the suspect's identity.

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Military calls UK attack victim a model soldier

LONDON (AP) — The soldier brutally murdered in a suspected terrorist attack in London was a popular 25-year-old ceremonial military drummer and machine gunner, a father and a passionate fan of the Manchester United soccer team, the British military said Thursday.

Lee Rigby, of 2nd Battalion The Royal Regiment of Fusiliers, who had joined the army in 2006, was posted in Cyprus, Afghanistan and Germany before becoming a recruiter, assisting with duties in the Tower of London.

"All he wanted to do from when he was a little boy was be in the Army," Rigby's family said in a statement issued through the Ministry of Defense. "He wanted to live life and enjoy himself."

The family said that Rigby would "do anything for anybody," always looked out for his sisters and took a "big brother" role with everyone he met.

"He was a loving son, husband, father, brother, and uncle, and a friend to many," the statement added.

Rigby, nicknamed Riggers, was an important member of the Corps of Drums who was known for his good nature and wit, as well as his love of his hometown soccer team, fellow soldiers said. Two men believed to have extremist Islamic beliefs are suspected of attacking and killing him.

"He was one of the battalion's great characters, always smiling and always ready to brighten the mood with his fellow Fusiliers. He was easily identified ... on parade by the huge smile on his face and how proud he was to be a member of the Drums," Warrant Officer Class 1 Ned Miller said in a statement issued by the defense ministry. "He would always stop for a chat just to tell me Manchester United would win the league again."

The ministry said Rigby had a 2-year-old son, Jack.

"His loss will be felt across the battalion, but this is nothing compared to how his family must be feeling at this difficult time," said Capt. Alan Williamson, the adjutant of the 2nd Fusiliers in the statement.

A small group of mourners gathered Thursday at a church in Woolwich near where Rigby was killed to remember him. The Rev. Christopher Chessun said he had come to show solidarity with members of all faiths shocked by the killing.

Help for Heroes, a military support charity, said it was working hard to keep up with the many people who were showing their solidarity by buying T-shirts and hoodies.

Muslim hard-liners ID suspect in London attack

In this undated image released Thursday May 23, 2013, by the British Ministry of Defence, showing Lee Rigby known as ‘Riggers’ to his friends, who is identified by the MOD as the serving member of the armed forces who was attacked and killed by two men in the Woolwich area of London on Wednesday. The Ministry web site included the statement "It is with great sadness that the Ministry of Defence must announce that the soldier killed in yesterday's incident in Woolwich, South East London, is believed to be Drummer Lee Rigby of 2nd Battalion The Royal Regiment of Fusiliers." (AP Photo / MOD)

Police officers lay down floral tributes handed to them by members of the public at the scene of a terror attack in Woolwich, southeast London, Thursday, May 23, 2013. The British government’s emergency committee met Thursday after two attackers killed a man in a daylight attack in London that raised fears terrorism had returned to the capital. (AP Photo/Sang Tan)

LONDON (AP) — A man seen with bloody hands wielding a butcher knife after the killing of a British soldier on the streets of Londonwas described as a convert to Islam who took part in demonstrations with a banned radical group, two Muslim hard-liners said Thursday.

Police raided houses in connection with the brazen slaying of the off-duty soldier, identified as Lee Rigby, of the 2nd Battalion The Royal Regiment of Fusiliers, who served in Afghanistan. In addition to the two suspects who were hospitalized after being shot by police, authorities said they had arrested a man and a woman, both 29, on suspicion of conspiracy to murder.

Police would not say whether it appeared Rigby had been targeted specifically because of his military service. Although he was not in uniform at the time he was killed, he was said by witnesses to be wearing a T-shirt for a British veterans' charity.

Authorities have not identified either of the two wounded suspects and have not said when they would do so. Officials in Britain usually wait to name suspects until charges have been filed.

Anjem Choudary, the former head of the radical group al-Muhajiroun, told The Associated Press that the man depicted in startling video that emerged after Rigby's death was named Michael Adebolajo, a Christian who converted to Islam around 2003 and took part in several demonstrations by the group in London.

The BBC broadcast video from 2007 showing Adebolajo standing near Choudary at a rally.

Omar Bakri Muhammad, who now lives in Lebanon but had been a radical Muslim preacher in London, also said he recognized the man seen on TV as Adebolajo and said he attended his Londonlectures in the early 2000s.

Bakri, speaking from Lebanon, said he remembers Adebolajo as a "shy person" who was keen to learn about Islam and asked interesting questions.

"He used to listen more than he spoke," Bakri said. "I was very surprised to learn that he is the suspect in the attack."

Mary Warder, who has lived in the Woolwich area for more than 30 years, told the AP said she had seen both of the suspects preaching on the streets. Shopkeepers, however, said they couldn't remember seeing them.

The two men suspected of killing the 25-year-old Rigby had been part of previous investigations by security services, a British official said Thursday, as investigators searched several locations and tried to determine whether the men were part of a wider terrorist plot.

There also was no clear indication on when or where the suspects may have been radicalized.

Rigby, the father of a 2-year-old boy, was slain Wednesday afternoon outside the Royal Artillery Barracks in the Woolwich area of south London while horrified bystanders watched in the busy city known for its decorum.

The bizarre scene was recorded on witnesses' cellphones, with one of the two suspects boasting of their exploits and warning of more violence as the soldier lay on the ground. Holding bloody knives and a meat cleaver, they waited for the arrival of police, who shot them in the legs, according to a passerby who tried to save the dying soldier.

A British government official said one of the two men tried to go to Somalia to train or fight with the terror group al-Shabab. The official, who spoke on condition of anonymity because he was not authorized to speak about the police investigation, would not say if the suspect had been arrested or whether he had made any other trips to the country.

Citing unidentified sources described as having "knowledge of British jihadis," the BBC's "Newsnight" program reported that one of the suspects in the attack was arrested last year on his way to joining al-Shabab.

Prime Minister David Cameron vowed that Britain would not be cowed by the horrific bloodshed, and that it would reject "the poisonous narrative of extremism on which this violence feeds." In Washington, President Barack Obama said the U.S. "stands resolute with the United Kingdom" in the fight against violent extremism.

There were few signs of alarm on the streets of London, which has been hit by terrorist attacks during a long confrontation with the Irish Republican Army and more recently, in July 2005, by al-Qaida-inspired suicide bombings that killed 52 commuters.

"It's hateful, it's horrific and upsetting. But it doesn't seem to have made much of a difference," Christian White, 43, said at King's Cross station, close to the site of one of the 2005 bombings. "Londoners are used to living in a city where life is complicated."

Even so, security was increased at military barracks and installations in the capital, with extra armed guards added in many cases. Police said extra patrols were added at sensitive areas, including places of worship, transport hubs and congested areas.

Both of the hospitalized suspects had been part of previous terrorism investigations by Britain's security services, according to a British official who spoke on condition of anonymity because he was not authorized to speak about the police inquiry and cautioned that details could jeopardize future trials.

It was unclear how recent the investigations were, whether the men were loosely tied to other suspects being investigated, or whether they themselves had been put under surveillance, which could have included being watched by undercover investigators or having their phone calls and emails intercepted.

Dramatic video showed a black man — animated, hands stained with blood and holding a meat cleaver — criticizing the British government and the presence of U.K. troops in foreign lands.

Maajid Nawaz, a former Islamist now with the London-based Quilliam anti-extremism think tank in London, said the video and emerging details indicated the men had been inspired by al-Qaida even though they may not have been directed by any specific affiliate to attack the soldier.

"There is always mood music playing before these attacks happen," Nawaz told the AP. "In this instance, I'm not saying they are operationally linked to al-Qaida, but these men clearly felt an affinity to this global jihadist zeitgeist. And they wouldn't have had to have visited any foreign countries for this ideology to have resonated with them."

Security officials have been worried over the recent increase of men seeking training and fighting opportunities in countries such as Syria, Somalia and Yemen.

Dozens of British men and women are said to have been radicalized by U.S.-born militant cleric Anwar al-Awlaki, the militant leader who was killed in a 2011 U.S. drone strike in Yemen.

A Twitter account used by members of Somalia's al-Shabab militant group made a lengthy post Thursday about the attack in Woolwich.

The Twitter account referenced the video in which the bloodied suspect called the attack "an eye for an eye." The tweet said the British army had a "woeful record of abuses" against Muslims worldwide.

"We swear by almighty Allah we will never stop fighting you," the man in the video declared, complaining about British troops fighting Muslims. "We must fight them as they fight us."

The camera then panned away to show a body lying on the ground. This video, with its venomous threats, may provide the lasting image of the tragedy.

Police in the eastern England county of Lincolnshire said a property was searched in connection to the Woolwich attack. Police said a search warrant had been obtained but would not provide details. Police were also scouring the attack site for further clues.

There also was a police raid on a public housing complex in east Greenwich just outside of London thought to be related to the investigation.

One man was arrested Wednesday outside a mosque in Essex after he threw a smoke bomb, police said. He was also found to be carrying knives and is expected in court Friday. No one was injured.

Separately, police in Kent said they charged a 45-year-old man with religiously aggravated criminal damage and burglary. The man, Andrew John Grindlay, was arrested Wednesday night.

There were no incidents reported at London mosques. Police called for calm and said there were 1,200 officers deployed on the streets.

Britain's security threat remained the same since the killing, but security officials said they were reviewing preparations for the June 17-18 Group of Eight summit in Northern Ireland. Obama and other world leaders are expected to attend.

Police defended the speed of the department's response to the Woolwich attack. Assistant Commissioner Simon Byrne said police were on the scene nine minutes after receiving the first emergency call. Once it became clear that guns were involved, firearms officers were called and arrived 14 minutes after the first call to police, he said.

The Ministry of Defense said Rigby, who joined the army in 2006, was a machine gunner posted in Cyprus, Afghanistan and Germany before becoming a recruiter who assisted with duties in the Tower of London.

Nicknamed "Riggers," he was an important member of the Corps of Drums who was known for his good nature and wit, and his love of his hometown soccer team, Manchester United, according to fellow soldiers.

"He was one of the battalion's great characters, always smiling and always ready to brighten the mood with his fellow Fusiliers. He was easily identified ... on parade by the huge smile on his face and how proud he was to be a member of the Drums," Warrant Officer Class 1 Ned Miller said in a statement issued by the ministry.

Rigby's family said he would "do anything for anybody," always looked out for his sisters and took a "big brother" role with everyone he met.

"He was a loving son, husband, father, brother, and uncle, and a friend to many," the family said in a statement issued by the ministry.

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Associated Press writers Cassandra Vinograd, Sylvia Hui, Matt Surman and Danica Kirka in London and Zeina Karam in Beirut contributed to this report.

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