WASHINGTON (Reuters) - The White House said on Monday the defection of Syria's prime minister showed that President Bashar al-Assad's government was "crumbling from within" and repeated the U.S. call for him to step aside and end the violence gripping the country.

"This is a sign that Assad's grip on power is loosening. If he cannot maintain cohesion within his own inner circle, it reflects on his inability to maintain any following among the Syrian people that isn't brought about at the point of a gun," White House spokesman Jay Carney told a news briefing.

"The momentum is with the opposition and with the Syrian people. It's clear that these defections are reaching the highest levels of the Syrian government and Assad cannot restore his control over the country because the Syrian people will not allow it," he said.

The latest defection "only reinforces that the Assad regime is crumbling from within and that the Syrian people believe that Assad's days are numbered," Carney said.

In one of the highest-profile desertions from Damascus, Syrian Prime Minister Riyad Hijab on Monday fled the country. While not part of Assad's inner circle, his departure provides a powerful morale boost to the opposition.

Like the rebels, Hijab is from Syria's Sunni Muslim majority, while Assad is from the Alawite minority.

The United States has sought to increase pressure on Assad to leave power for more than a year.

U.S. intelligence officials expect pro-Assad and opposition forces to be in the fight for the long haul and are not predicting a near-term end to the Syrian conflict.

But U.S. officials say the defections are making a dent.

"It stands to reason that mounting defections are taking a psychological toll on the regime," a U.S. official said on condition of anonymity. "There's probably a range of motivations for why people are breaking with Assad, from self-preservation to an inability to tolerate his ruthless tactics."

"The impact of defections on regime stability will depend in part on the role these people play in the opposition," the official said. "And with the heat on the regime rising, Assad may be starting to wonder about the loyalty of some in his inner circle."

Former U.N. Secretary-General Kofi Annan announced last week he would resign his post as U.N.-Arab League Joint Special Envoy for Syria after Assad failed to respect the terms of a U.N.-backed peace deal and after China and Russia refused to support increased sanctions on Syria.

At the White House, Carney said the Obama administration would continue working with other countries and with Syria's opposition to keep pressure on Assad and encourage a peaceful political transition there.

(Reporting By Laura MacInnis and Tabassum Zakaria; Editing by Mohammad Zargham and Xavier Briand)

Sen. Bernie Sanders delivers a scathing analysis of the inequality of income the prevails in America and is increasing by the year. Posted Aug. 3, 2012. Thanks to Christina.

A man sits on top of his house's roof as floods rise in suburban Quezon City, north of Manila, Philippines on Tuesday Aug. 7, 2012. Torrential rains pounding the Philippine capital on Tuesday paralyzed traffic as waist-deep floods triggered evacuations of tens of thousands of residents and the government suspended work in offices and schools.(AP Photo/Aaron Favila)

MANILA, Philippines (AP) — Torrential rains pounding the Philippine capital on Tuesday paralyzed traffic as waist-deep floods triggered evacuations of tens of thousands of residents and the government suspended work in offices and schools.

Incessant downpours set off by the seasonal monsoon overflowed major dams and rivers in Manila and nine surrounding provinces and put authorities on alert. The death toll from last week's Typhoon Saola, which battered Manila and the northern Philippines for several days, has climbed steadily to 51.

The head of the government's rescue agency, Benito Ramos, said there were no immediate reports of new casualties early Tuesday after the rains pounded already saturated Manila for more than 24 hours.

Vehicles and even heavy trucks struggled to navigate water-clogged roads, where hundreds of thousands of commuters were stranded overnight. Many cars were stuck in the muddy waters.

The La Mesa dam, which supplies water to the capital of 12 million people, spilled excess water for a second time early Tuesday into the rivers flowing into Quezon city, a middle-class Manila suburb, as well as the neighborhoods of Malabon, Valenzuela and Caloocan, where several villages were submerged.

Along the swollen Marikina River, police were deployed to move more than 5,000 residents away from the riverbanks in what Vice Mayor Jose Cadiz said was an enforced evacuation. The operation started after the City Hall sounded the alarm bell.

The Philippine Stock Exchange in the financial district of Makati, which was also flooded, was closed Tuesday. Also closed was the U.S. Embassy along Manila Bay in the historic old city, which was drenched out last week when a storm surge pushed the water over the seawall.

"The embassy is closed today due to excessive flooding in the streets and concern for the safety of our employees and consular applicants," Ambassador Harry Thomas Jr. said in an announcement.

The military, which is involved in rescue work, canceled several events due to the flooding, including an awarding of bounties to tipsters who helped troops capture al-Qaida-linked militants.

In 2009, massive flooding spawned by a typhoon devastated Manila and the surrounding areas and killed hundreds of residents in rampaging flash floods. The state weather bureau said the current flooding was not as severe but warned of more rainy days ahead.

Typhoon Saola was the seventh of 20 typhoons and storms expected to batter the Philippines this year.