The attack raised the number of dead soldiers to five in 24 hours, making the past week, with 14 deaths, the worst since US troops seized Baghdad on April 9.

"At 2:35 am (2235 GMT Saturday), a marine was killed and one wounded during a grenade attack by a bridge" in Al-Haswat, 30 kilometres (20 miles) south of Baghdad, a military spokesman said.

Four soldiers were killed Saturday, as violence climbed after the US coup of killing Saddam's dreaded sons, Qusay, his heir apparent, and Uday, the sadistic playboy, on Tuesday.

Even as US forces reveled in their biggest victory since the overthrow of Saddam, this month's 27 deaths in guerrilla-style attacks accounted for more than half the 49 killed since largescale fighting was declared over on May 1.

The hunt for Saddam carried on late Sunday as US forces stormed a house in Baghdad's wealthy Mansour neighborhood, said the home's owner, himself a relative of the former president.

Witnesses said five people were killed as US troops raided the house, but a US soldier at the site said they were only returning fire. It was not immediately possible to confirm the toll.

Troubles for US troops also seemed to be spreading south into the heartland of Iraq's 15-million strong Shiite majority, so far tacit backers of the US presence in Iraq, as residents said a demonstrator was killed during street protests in the holy city of Karbala.

US marines fired shots, killing one person and wounding three others, after people in the 300-strong crowd hurled rocks at the soldiers, witnesses said.

The demonstration was held amid charges marines threw a smoke grenade Saturday night during a patrol near the city's tomb for Hussein, the grandson of the prophet Mohammed, revered by Shiites.

The US military, meanwhile, ignored the simmering social discontent and mounting casualties as they continued to insist they were winning the battle against the holdouts from Saddam's regime.

US Joint Chiefs of Staff chairman General Richard Myers, touring the country, said Iraqis were coming forward more and more with information since Saddam's sons were killed.

"What I found today ... there's been a big spike in Iraqis coming forward, about weapons caches and where people are," said Myers who arrived from Kuwait and toured the area of Tikrit, the hometown of Saddam, north of Baghdad.

He stressed the insurgent attacks were not being directed by Saddam, who he described as desperate and on the run.

"The point is about Saddam Hussein is he is so busy surviving, he is having no impact, no impact on the security situatiuon here. He is trying so hard to save his own skin," said Myers.

Despite seeing footage of the mutilated corpses on television and photos of the bodies in newspapers Sunday, many Iraqis dismissed Uday and Qusay's last stand in the northern town of Mosul as a sort of cover-up by the United States.

A senior coalition official said the fate of the bodies of the slain brothers would be decided in the next 24 hours, following consultations with the US-sponsored 25-member Governing Council and religious figures.

In other developments, four US soldiers serving in Iraq have been charged with abuse of Iraqi prisoners of war and were awaiting a decision on whether they will face a court martial, Cental Command said.

The charges mark the first time that US personnel have been formally accused of mistreating Iraqi prisoners since the beginning of the US-led invasion of Iraq on March 20.

And a spokesman for the Coalition Provisional Authority said the airport in the main southern city Basra would reopen shortly.

WAR.WIRE