With April less than halfway through, the US military said coalition forces had lost about 70, and killed about 10 times that number of "rebels" this month.

The occupation forces' toll compares to 89 killed in action in the three-week war that toppled Saddam. At least 474 US troops have died in combat since the war began in March last year.

With President George Bush seeking re-election in November and Iraq high on the campaign agenda, the US-led occupation administration in Baghdad said it was vital to defeat armed resistance before a planned US handover of power to Iraqis on June 30.

"It is critical that we cleanse the Iraqi body politic of the poison that remains after 35 years of Saddam Hussein's totalitarian rule," said spokesman Dan Senor. "The task will only become more difficult down the road."

The US Central Command chief, General John Abizaid, said: "There is not a purely US military solution to any of the particular problems that we're facing here."

Truce extension

Despite some overnight clashes in Falluja, 50km (30 miles) west of Baghdad, Iraqi mediators said they had secured an extension to a truce that gave the town some respite at the weekend.

Muhammad Qubaisi, of the Iraqi Islamic party, said more talks were expected on Tuesday.

However, US Brigadier General Mark Kimmitt said US marines were ready to "complete the destruction of enemy forces" in Falluja, unless political negotiations produced results.

Kimmitt had no word on civilian deaths.

Rafia Hayad al-Issawi, director of Falluja's main hospital, said he believed more than 600 Iraqis had been killed in the town.

The marines attacked anti-occupation groups in Falluja last week in response to the murder and mutilation of four American private security guards ambushed in the town on 31 March.

Kimmitt said US-led forces had deployed "a significant amount of combat power" to secure roads west and south of Baghdad.

But the fighters struck again, setting a US military truck ablaze on the road to Baghdad airport, witnesses said.

Many Iraqis, including some Governing Council members, have been shocked at the ferocity of the Falluja fighting.

Fleeing civilians said they were haunted by the violence.

"I could see many bodies in the streets. Hundreds were lying in the street," said Samir Rabia, who escaped with relatives and eight other families in the back of a refrigeration truck.