Days after the first reports that Russian forces fighting in Syria were using cluster bombs – a type of weapon banned by many countries around the world – the New York-based Human Rights Watch reported that it had obtained evidence that a new, advanced form of cluster weapon, manufactured in Russia, is being used against Syrian rebels.

Cluster bombs, or cluster munitions, are typically made up of a shell containing smaller “bomblets”– sometimes hundreds or more. The smaller bombs disperse over a wide area when the shell releases them, but in practice, many don’t explode immediately. They can remain dangerous for years, and have caused an untold number of civilian deaths and injuries even years after the conflict in which they were used has ended.

Related: Obama Abandons $500 Million Program to Train Syrian Rebels

According to Human Rights Watch, the group has received evidence of both air-dropped and ground-launched cluster munitions being used in Syria, including most recently bombs containing SPBE sensor-fused sub-munitions, a variety meant to be used against armored vehicles. The bomblets in the device fire “an explosively formed slug of molten metal” downward at their targets.

“It’s disturbing that yet another type of cluster munition is being used in Syria given the harm they cause to civilians for years to come,” said Nadim Houry, deputy Middle East director at Human Rights Watch. “Neither Russia nor Syria should use cluster munitions and both should join the international ban without delay.”

Unexploded cluster bomb

"BLU-26 cluster sub-munition" by Seabifar G

The Human Rights Watch report did not attempt to determine whether Russian forces operating in Syria had used the weapons or whether they had simply been provided to Syrian forces by Russia.

Russian involvement in Syria has come under considerable U.S. criticism in the past two weeks, but the White House is unlikely to have any public comment on the use of cluster weapons in Syria, because the United States itself is one of the countries that has refused to sign a ban on such weapons.

Related: Putin’s Missiles Take Out Terrorist Iranian Cows

The Human Rights Watch report on cluster bombs in Syria comes as Russia is claiming considerable success in what it describes as a fight against the terror group ISIS, but which international observers say has actually been bomb and missile attacks focused on different rebel groups that are opposed to the government led by dictator Bashar al-Assad.

Over the weekend, Russian President Vladimir Putin contradicted earlier statements by senior military officials who had said that Russian ground troops, characterized as “volunteers” might participate in the fighting.

“Whatever happens, we’re not going to do this, and our Syrian friends are well aware of it,” he said in an interview on Russian television.

As has been his habit, Putin also took a shot at Western powers, suggesting that Russian involvement in Syria, seen by many in the West as surprising, had come with warning.

Related: Trump Gets an Endorsement from Putin’s Crimean Crony

“We advised beforehand our American partners and many other partners, particularly those in the region, about our intentions and our plans,” Putin said in the same interview.

Russia, he added, was “never ever” warned about similar operations by Western countries.

“Yet we did so. With good will, on considerations of practicability and to show our openness for cooperative work,” Putin said. “I want to stress once again that we are acting in full compliance with international law, and at the request of the official authorities of Syria

Putin’s forces are in Russia at the request of Assad, meaning that his claim is correct, if one views the Assad regime as legitimate – an increasingly fraught question in the region.

Beirut (AFP) - Syria's leading Kurdish militia and several Arab rebel groups that have fought alongside it have formalised their alliance in a new group called the Syrian Democratic Forces.

The formation of the alliance comes after Washington said it was abandoning a plan to train and equip rebels to fight the Islamic State group and could provide the US with a new partner in the battle against the jihadist group.

The alliance was announced in a statement published online by a spokesman for the Kurdish People's Protection Units (YPG).

"The sensitive stage through which our country Syria is passing and the rapid developments on the military and political front... require a united national military force for all Syrians, including Kurds, Arabs and Syrians and all others," the statement said.

The alliance includes several Syrian rebel groups that have backed the YPG in battles against IS, including the mostly-Arab Burkan al-Furat group.

Groups representing Arab tribes and Syriac Christians are also listed as participating in the new force.

View gallery

A fighter from the Kurdish People's Protection Units (YPG) sits on a tank after they recaptured …

Washington has already partnered with the YPG to battle IS in parts of northern Syria, with the US-led coalition providing Kurdish forces with air cover as they fought the jihadists on the ground.

But the growing strength of the YPG has rattled neighbouring Turkey, which considers the group a branch of the outlawed Kurdistan Worker's Party.

And the strong ties between Washington and Syria's Kurds have also caused resentment among other Syrian rebel groups who have lobbied for US air support and weapons.

The YPG has had several successes in ousting IS from areas of northern Syria, backed by groups like Burkan al-Furat.

In January, they pushed IS out of the border town of Kobane after four months of fighting and heavy US-led airstrikes.

And in June, they seized the key town of Tal Abyad from the jihadists, depriving them of a main transit point on the way to their de facto Syrian capital Raqa.

Much of the Syrian opposition has regarded the Kurds with suspicion because of the careful line they have walked since the uprising began in March 2011.

Despite years of repression by Damascus, they declined to take up arms against the regime and have instead focused on building autonomous governance in Kurdish-majority regions.

DAMASCUS, Syria (AP) — Russian jets intensified their airstrikes Monday in a central Syrian province as government and allied troops pushed out insurgents from local villages to expand their control of the area, activists and a military statement said.

The advance is the latest in a government bid to regain control of areas in the rural parts of Hama province, and the Sahl al-Ghab plain. The plain links Hama to the northwestern rebel-controlled Idlib province and is adjacent to Latakia province, a stronghold of President Bashar Assad and the Alawite religious minority to which he belongs.

Meanwhile, the Russian Defense Ministry said it has struck 53 alleged Islamic State targets in the past 24 hours, destroying command centers, ammunition and fuel depots as well as camps where foreign militants are supposedly training. The ministry said the positions of the IS group were in the central provinces of Homs and Hama, as well as in Latakia and Idlib provinces. IS only has a limited presence on the edges of Hama, away from where the fighting has been concentrated.

Russia insists it is mainly targeting the Islamic State group and other "terrorists," but the ground-and-air offensive is being waged in areas controlled by mainstream rebels as well as the al-Qaida affiliate in Syria, the Nusra Front. A coalition of rebels, which includes the Nusra Front, controls the province of Idlib, from which they pushed out Assad's forces in September, in one of the most serious setbacks for the government.

On Monday, activists said the airstrikes pounded the village of Kfar Nabudeh, in the western part of Hama and strategically located less than 10 miles from a major town on the Idlib highway, Khan Sheikhoun.

The Britain-based Syrian Observatory for Human Rights said at least 30 airstrikes were reported in Kfar Nabudeh while government troops and Lebanon's Hezbollah fighters entered the village from the south. Another activist-operated media platform, the Shaam News Network, said the fighting was inside the village as insurgents ambushed government forces in the village reported to be laden with underground tunnels.

However, a Syrian military statement said it took control of the village, and others nearby. There was no way to independently verify the competing claims.

During the last six days of ground operations, government troops have moved in on two villages in eastern Hama, Atshan and Tal Sukayk, and a third in the plain area. Activists say rebels seized one village south of Idlib.

The Russian defense statement said its jets have hit mortar positions around Tal Sukayk in the last 24 hours, as well as a training camp for foreign militants in Mastouma in Idlib. The ministry said it used Su-34, Su-24M and Su-25SM planes to strike the targets.

"The terrorists in the past days were desperately trying to transport ammunition, armaments, fuel and supplies from Raqqa to the frontline," the ministry said, in reference to the northern province controlled by the Islamic State group, adding that a "significant part" of their supplies have been destroyed by Russian airstrikes. Raqqa province is under IS control and contains the group's de facto capital in Raqqa city.

___

El Deeb contributed from Beirut. Associated Press writer Nataliya Vasilyeva in Moscow contributed to this report.