As US forces pressed on with a sweep of Iraq’s lawless west for Abu Musab al-Zarqawi and his militants, aid workers reported that hundreds of families had fled the fierce fighting near the Syrian border.

Prime Minister Ibrahim Jaafari announced that because of the continuing security crisis, he was extending for 30 days the state of emergency in force across Iraq, except for three Kurdish provinces in the northern mountains.

The emergency, first introduced in November, allows the government to impose curfews, issue arrest warrants and restrict movement around the country.

In the latest violence, a suicide bomber drove his explosives-laden car at a truck transporting Iraqi soldiers in Baquba, north of the capital, killing two soldiers and a civilian.

Four more soldiers were wounded in a second car bomb attack on a convoy in the nearby village of Saif Saad.

A policeman was shot dead and five people wounded when gunmen opened fire on a police patrol in western Baghdad.

In northern Iraq, two soldiers and three rebels were killed in clashes near Shurgat, south of the region’s main city of Mosul.

Near the key refinery town of Baiji further south, one bomb killed a civilian while another killed one US soldier and wounded four.

The soldier’s death brought US losses since Saturday to 21 — one of the deadliest periods for US troops in Iraq since the 2003 invasion.

The surge in violence, including an unprecedented string of car bombings, has left more than 400 dead since the start of the month and has hobbled efforts by Prime Minister Jaafari’s new Shiite-dominated government to seize the political initiative and rally the restive Sunni Arab former elite to his side.

US officials have been quietly pressing the Iraqi government to include more Sunnis, especially in the constitutional committee, the New York Times reported.

“There is a growing sense of alarm about this in the US government,” said a senior official the paper did not name. Yet most Sunnis insist they will not rejoin mainstream politics until Washington has set out a pullout timetable.

Iraqi President Jalal Talabani argued that “the wave of violence is a sign of the terrorists’ weakness.

“The only recourse they have left are car bombs. They have lost control of various cities and have been surrounded,” he told the Brazilian daily Folha de Sao Paulo.

Meanwhile, US marines pressed on with their largest military operation since the assault on the rebel enclave of Fallujah west of Baghdad last November.

“Operation Matador” was launched on May 7 in the Al-Qaim area near the Syrian border, across which US commanders charge much of the insurgents’ weaponry and foreign volunteers are smuggled in.

The area is a stronghold of Abu Musab al-Zarqawi, the Al-Qaeda leader who has a 25 million dollar bounty on his head and has claimed some of the bloodiest attacks in Iraq.

The US military said F-18 jets bombed a house occupied by at least four gunmen in the area on Thursday.

The marines, who have some 1,000 men engaged in the operation, claim they have killed more than 100 rebels over the past five days. Zarqawi’s network denied the losses and claimed his own men had killed 40 US troops.

The Iraqi Red Crescent has started distributing supplies to families who fled the fighting.

Some 350 families fled the town of Al-Qaim into the western desert, Red Crescent spokesman Mazen Abdallah said.

A prominent Shiite religious politician meanwhile called for a new purge of the civil service to eliminate former high-ranking members of Saddam Hussein’s Baath party.

“Today there are 100,000 high-ranking Baathists in Iraq and it is up to the government to purge the country of them,” said Sheikh Sadreddin al-Kubbanji, a leader of the Supreme Council for the Islamic Revolution in Iraq (SCIRI).

“By a purge, we mean they should not be allowed into any important decision-making posts, not that they should be physically liquidated,” he told worshippers at the main weekly Muslim prayers in the central Shiite shrine city of Najaf.