NAJAF, Aug 22: Heavy clashes flared between US troops and militiamen in Najaf on Sunday after the suspension of a proposed hand over of the militia's shrine stronghold to Iraq's religious leadership.

Despite the rumbling crisis, which has helped world oil prices to historic highs, crude exports from southern Iraq returned to their normal level overnight, the state-owned firm which operates the fields said.

Fighters loyal to Shia leader Moqtada Sadr launched multiple attacks on US tanks, parked around 300 metres away from the Imam Ali shrine, as the reverberations of gunfire and mortar bombs could be heard from inside the mosque compound, a correspondent on the scene said.

US helicopters later hovered over the shrine area, as the fighting petered out into random mortar attacks. A correspondent said that Sunday's clashes were more intense than the sporadic firing the previous day.

Overnight, US warplanes pounded the city, causing three large explosions near the mausoleum. Some two days after spokesmen for both Sadr and Grand Ayatollah Ali al-Sistani announced the deal to hand over the keys to the shrine, which the Mehdi Army have occupied since their April uprising, talks snagged.

"We do not know how long it will take. It all depends on the situation and Sistani," Sadr's junior spokesman Sheikh Ahmed al-Shaibani said in Najaf. "The matter is suspended as of now, because we are awaiting the response from Sistani about forming the committee" tasked with carrying out a full inventory of the shrine's priceless works of art and alms.

Five US troops have been killed and another wounded in the last 24 hours in a series of attacks and an accident, the military said on Sunday. One soldier was killed when a roadside bomb exploded at around 4:45 pm (1245 GMT), in the main northern city of Mosul, said a statement.

Three US marines were killed in Al-Anbar on Saturday, one in action and two died from wounds received in separate attacks on the same day, said another statement. Another marine also died in a road accident when his Humvee ploughed into a US tank, flipped and crashed in the province, which is home to the infamous flash point cities of Fallujah and Ramadi.

In Al-Khalis, north-east of Baghdad, two people were killed and at least eight wounded when a suicide bomber blew up a parked car as the deputy provincial governor's convoy drove past, police and medics said.

One Indonesian and two Iraqis were killed and a Philippine wounded when their convoy was ambushed in Mosul, police said. Polish Defence Minister Jerzy Szmajdzinski said his government wanted to pull its troops out of Iraq as soon as possible, the PAP news agency reported. -AFP