Fallujah, Iraq ? Thousands of women and children fled this war-ravaged city Friday as the U.S.-led coalition sought to regain large swaths of the country now under the control of anti-American militias while seeking to stave off a revolt from its handpicked governing council.

On the anniversary of the fall of Saddam Hussein’s regime, authorities reported Friday that five more U.S soldiers were killed in the last two days, bringing to 49 the number of American troop deaths since Sunday. It was the deadliest week for the U.S-led occupation since Saddam’s ouster.

Iraqi insurgents declared they had taken six more hostages Friday, two Americans and four Italians, a day after militants showed footage of three captured Japanese aid workers whom they threatened to burn unless their country withdrew their troops from Iraq.

By most accounts, the Iraqi dead numbered in the hundreds. In Fallujah, Iraqis took advantage from a lull in the fighting to bury dozens of their dead in makeshift graves in the city’s soccer stadium.

A week of intense fighting between coalition troops and a variety of Sunni and Shiite militias triggered concern that the coalition had lost control of the country.

“The lid of the pressure cooker has come off,” British Foreign Secretary Jack Straw told British Broadcasting Corp. Radio. “There is no doubt that the current situation is very serious and it is the most serious that we have faced.

“It is plainly the fact today that there are larger numbers of people, and they are people on the ground, Iraqis, not foreign fighters, who are engaged in this insurgency.”

Despite the widespread revolt, U.S. authorities here sought to cast the turmoil in the best light.

“It’s a gross mischaracterization to say the entire country is at war,” Brig. Gen. Mark Kimmitt said Friday. “The entire country is under combat.”

On the first anniversary of the fall of Baghdad, an American soldier removes posters of Shiite cleric Muqtada al-Sadr that were hanging on a statue on Firdos Square in Baghdad, Iraq. One year ago Friday, U.S. soldiers pulled down Saddam Hussein's statue from the same location.

Secretary of State Colin Powell took to the airwaves Friday afternoon, conducting a series of broadcast interviews seeking to assure U.S. viewers that developments did not signal a loss of U.S. control over Iraq.

Powell reiterated administration statements that the burst of violence was caused by “remnants of the old regime” and the militia of anti-American Shiite cleric Muqtada Sadr “that doesn’t represent all of the Shi’a people.”

“And those elements haven’t been fully dealt with yet,” Powell said. “But they will be dealt with.”

As the United States sought to stamp out uprisings across central and southern Iraq, its civilian administrators faced a different kind of turmoil in Baghdad. A Shiite member of the Iraqi Governing Council suspended his membership in the 25-person body and four others threatened to follow suit to protest what they described as collective punishment of Fallujah residents by U.S. Marines surrounding the city.

“We condemned U.S. military operations in Fallujah which was a form of mass punishment in response to” last week’s killing and mutilation of four U.S. security contractors, Adnan Pachachi, a senior member of the Governing Council, told Al Arabiya television.

Much of Friday’s hostilities occurred in Fallujah, where a noon cease-fire offered some hope that residents of the Sunni Triangle city would get some reprieve from five days of heavy combat. Some 450 residents have been killed and more than 1,000 have been injured, according to hospital officials.