Baghdad: US military forces killed 11 members of a Mahdi Army splinter group southeast of Baghdad early on Thursday, American officials said. The raids were the deadliest against breakaway members of the militia in months.

It was not immediately clear if the action would impact a six-month freeze on activities that the militia's leader, radical Shiite cleric Moqtada Al Sadr, called in August and has signalled in the past week he might extend.

In the past, Al Sadr has said that any Mahdi Army members who do not abide by his freeze would no longer be considered members of the militia. But he has also indicated that his fighters have the right to defend themselves if attacked by US forces.

Al Sadr's order to halt activities has been credited by American commanders as one reason why violence in Iraq has fallen dramatically in the past six months. However, it is unclear how much control Al Sadr maintains over his fighters as groups have splintered from the main movement.

Yesterday's fighting took place in the early morning hours in Kut, 160 kilometers southeast of Baghdad, a local police officer said on condition of anonymity because he was not authorised to speak to the press.

The officer said eight militia members were killed. The US military said in an e-mail to The Associated Press that it killed an "estimated" 11 fighters. The reason for the discrepancy was not immediately clear.

In a later statement, the US military said the operation was targeting a suspect who was "reportedly responsible for attacks against Coalition forces". Troops approaching the target were fired at with assault rifles and rocket propelled grenades, the military said. They then called in support aircraft. The local police official said at least two US helicopters were used in the attack, along with an unknown number of fighter jets. The military said no suspects were detained during the raid and that no US troops were killed or wounded.

Despite the its freeze on activities, US commanders have in the past said they would not stop targeting splinter elements of the Mahdi Army that they said continue to operate, despite Al Sadr's order.

In early October, US forces killed 25 Shiite militia fighters in Khalis, north of Baghdad, who were believed to be part of a Mahdi Army splinter group

Inmate amnesty Bill

A proposed amnesty Bill for a portion of prisoners being held in Iraq's prisons came under criticism from a Sunni lawmaker, who said the matter should be left to the judicial system and that the bill would likely be shelved in parliament.

But the measure will not be brought to parliament for debate until March at the earliest, said Sami Al Askari, a key adviser to Prime Minister Nouri Al Maliki.

Iraq's Cabinet on Wed-nesday approved a draft of a general amnesty Bill for detainees being held in Iraqi prisons, a measure that could go a long way toward reconciling Iraq's warring factions.