Two American soldiers were killed and one wounded in an ambush near the oil city of Kirkuk as armed resistance to the US occupation gathered strength in northern Iraq.
The deaths brought to 103 the number of US soldiers killed in hostile fire in Iraq since President George Bush declared major combat over on 1 May.
In Fallujah, 35 miles west of Baghdad, gunmen attacked a US military convoy yesterday morning, setting a truck carrying ammunition ablaze and setting off a series of explosions. The gunmen fired on American soldiers caught in the blast, who returned fire.
The explosions sent burning shrapnel and plumes of black smoke into the air. Six wounded Iraqis were taken to hospital in Fallujah, one of whom later died, hospital officials said.
Young Iraqis danced in celebration by the road as the ammunition detonated and drivers honked their horns to show approval of the attack.
Fallujah, on the road to Jordan, is notorious for its support for the resistance and has been the scene of many ambushes.
US troops who approached the blazing vehicles, believed to be two Humvees and a truck, were fired on by rocket propelled grenades (RPGs) and machine guns, said witnesses. "Shells were flying everywhere like fireworks," said Khalil al-Qubaise, a shopkeeper.
The ambush in Kirkuk, 160 miles north of Baghdad, happened at 10.45pm on Saturday night when a patrol in vehicles was attacked with RPGs and small arms fire, an American spokesman said. A few hours later another attack with grenades and machine-guns on US troops near Hawija, west of Kirkuk, ended with five Iraqis killed. Another five men were arrested after a brief firefight north of Baiji, near Kirkuk.
Until a month ago, Kirkuk - captured by the Kurds in the war, and ethnically divided between Kurds, Arabs and Turkomans - had seen few military actions against US troops. But incidents are now almost daily amid signs that the resistance in Sunni-Muslim northern Iraq is becoming better co-ordinated and is extending its reach.
The US army in Iraq appears to be road bound, sending vehicles on patrol which are proving vulnerable to attacks by RPGs and bombs concealed in or beside the road.
A foreign military observer who saw the aftermath of a bomb attack on a US convoy on the road west of Baghdad on Saturday which killed one US soldier noted that "it was very professionally staged with the middle vehicle in the convoy exactly targeted".
Kerbala, where three US soldiers, including a colonel commanding a military police battalion, were killed late on Thursday night, was calm yesterday. US tanks had withdrawn from the centre of the city, which is holy to Shia Muslims. But the main road into it was blocked by Polish troops and the city could only be reached by a winding country road through groves of date palms.
Ali, an Iraqi policeman, who said he was with the US patrol when the fighting started, said that Lieutenant Colonel Kim Orlando had just spoken to the senior Shia cleric about his armed guard being on the street after the 9pm curfew when one of the guards suddenly opened fire without orders. Lt Col Orlando was killed immediately as were two Iraqi policemen who were with him.
The troubles now plaguing the US in Iraq might have been avoided, or at least reduced, if the Pentagon had paid more heed to a State Department study foreseeing many of those difficulties.
The assessment contrasted vividly with the rosy pronouncements of Paul Wolfowitz, the deputy Secretary of Defence and other civilian officials at the Pentagon, that rebuilding after the overthrow of Saddam Hussein would be relatively speedy and inexpensive.
Among the most striking predictions of the Future of Iraq Project, the year-long effort by the State Department, were that Iraq's infrastructure would be found to be in a far more dilapidated condition than generally believed, and that widespread looting could occur after the American-led invasion.
It also warned against the total disbandment of the pre-invasion Iraqi army, a step that Paul Bremer, the civilian administrator, took and almost certainly now regrets.
* President George Bush said yesterday that an audiotape purportedly by Osama bin Laden was evidence that the terrorist remains a global threat. The tape, broadcast throughout the Arab world by Al-Jazeera television, contains threats of suicide attacks "inside and outside" the US. It also singled out countries supporting the US occupation of Iraq, including Britain.