Elsewhere, a parked car bomb killed seven people and wounded 45 near a popular kebab restaurant in the city of Kirkuk, 250km north of Baghdad.

US casualties

Meanwhile, seven more US troops have died in Iraq, including three marines and a sailor killed on Tuesday in the province of Diyala north of the capital.

The latest fatalities took to 3,641 the US
military's losses in Iraq since March 2003 [AFP]

Another soldier was shot dead south Baghdad on Wednesday.

Earlier this week a soldier and a marine died of non-battle related causes in separate incidents.

The latest fatalities took the military's losses in Iraq since the March 2003 invasion to 3,641, according to an AFP count based on Pentagon figures.

Earlier on Thursday, the US military's second most senior commander in Iraq said US casualties seemed to be declining since May, calling it an "initial positive sign" that a five-month-old security plan was showing results.

"We topped out in May in casualties and we kind of predicted that because we went into areas that we had not been in for a long time and they were safe havens established by the extremists," Lieutenant-General Raymond Odierno said.

Iran accused

General Odierno said mortar and rocket attacks from Iraqi fighters had been hitting Baghdad's heavily protected Green Zone with greater accuracy in the past three months because of training from Iran.

His comments came after the US ambassador to Iraq accused Tehran of increasing support for such fighters when he met his Iranian counterpart for a second round of talks on Iraq's violence on Tuesday.

Iran rejects the allegations.