The violence flared after a government announcement that ousted dictator Saddam Hussein will go on trial on October 19 over a 1982 massacre of Shias, a decision branded by his defence lawyers in Amman as political meddling.

The two British soldiers died in a roadside bombing near Basra in southern Iraq, an area relatively free of the deadly insurgency that has gripped much of the rest of the country since Saddam was deposed in April 2003.

Their deaths bring to 94 the overall number of British personnel who have died as a result of combat, accident or natural causes in Iraq, according to the ministry of defence in London.

In the deadliest attack Monday, a suicide car bomber attacked a coalition base in the western town of Hit, killing 11 people and wounding 16, officials said.

In Baghdad, two policemen were killed and five wounded when rebels staged an audacious dawn raid on a checkpoint outside the interior ministry, a ministry official said.

Rebels arrived aboard four cars and sprayed machine-gun fire at police before fleeing, the official said.

Also in Baghdad, four US soldiers and three civilians were wounded in another suicide car bomb attack, US and Iraqi officials said. Three insurgents were killed in an ensuing exchange of gunfire.

The driver of a truck belonging to the North Oil Company was killed when a bomb exploded on a highway linking the northern town of Kirkuk to the oil refining centre of Baiji, security officials said.

Iraqi and US troops, backed by helicopters and fighter aircraft, continued to battle insurgents in the restive northern town of Tal Afar, where at least 13 rebels were killed Sunday, the US military said.

The casualties included seven rebels killed by helicopter fire after opening up on the forces from inside a mosque.

"Terrorists operating from within a mosque... engaged Iraqi and coalition troops... (who) were unable to suppress the barrage of machine gun and RPG (rocket-propelled grenade) fire and so they requested the assistance of coalition helicopters," a military statement said.

The helicopters returned fire on the mosque "immediately stopping the enemy salvo", the statement said.

The Iraqi army also reported that a US aircraft had fired on insurgents attempting to launch mortar attacks on a US military base near Balad, 75 kilometres (45 miles) north of Baghdad.

The insurgents were spotted by the overflying US aircraft which opened fire, killing four and wounding six, an Iraqi officer said.

The fighting came amid claims from lawyers for Saddam that an October 19 trial date set for the deposed Iraqi leader was politically motivated with no basis in law.

"It is all politics. It has nothing to do with the law," said Jordanian lawyer Issam Ghazzawi, spokesman of the Amman-based defence team.

"The announcement about the trial date is illegal because it was made by the official government spokesman and not by the court," Ghazzawi told AFP, referring to government spokesman Laith Kubba who made the announcement.

Kubba said Sunday that Saddam and seven former henchmen would go on trial on October 19 over the massacre of more than 140 Shia villagers.

He also suggested that if found guilty and sentenced to death, the execution could be carried out immediately.

A Western official said the Iraqi Special Tribunal, the official body organising the trials of former regime members, would make a statement within a few days to clarify Sunday's announcement.

The trial will take place just four days after a referendum on Iraq's draft constitution is due to be held, a document that has caused deep divisions between the ousted Sunni elite and majority Shias.

The Islamic Army in Iraq, an extremist Sunni group known for kidnapping and killing foreigners, issued an Internet statement urging Iraqis to vote no in the vote.

The document will need to be rewritten and resubmitted if two-thirds of voters in three of Iraq's 18 provinces say no, numbers the Sunni community could muster.