The calls reflect growing frustration with the inability of Iraqi security forces to prevent extremist attacks.

The weekend deaths included two American soldiers one killed Sunday in a suicide bombing on the western outskirts of Baghdad and another who died in combat Saturday in Salahuddin province north of the capital, the US command said. Three soldiers were wounded in the Sunday blast.

Sunday's deadliest attack occurred when a bomb struck a truckload of newly recruited Iraqi soldiers on the outskirts of Baghdad, killing 15 and wounding 20, a police official at the nearest police station said on condition of anonymity because he was not authorised to release the information.

Also Sunday, two car bombs exploded near simultaneously in Baghdad's mostly Shia Karradah district, killing eight people. The first detonated at 10:30 a.m. near a closed restaurant, destroying stalls and soft drink stands. Two passers-by were killed and eight wounded, a police official said.

About five minutes later, the second car exploded about a mile away near shops selling leather jackets and shoes. Six people were killed and seven wounded, said the official, who also spoke on condition of anonymity because he was not authorised to talk to the media.

The Karradah area includes the offices of the Supreme Islamic Council in Iraq, the biggest Shia party in parliament, and is considered among the safest parts of the capital.

Elsewhere, a bomb hidden under a car detonated Sunday at the entrance of Shorja market a mostly Shia area of central Baghdad that has been hit repeatedly by insurgents killing three civilians and wounding five, police said.

Police also reported they found the bodies of 29 men Sunday scattered across Baghdad presumed victims of sectarian death squads. Four other people were killed Sunday in separate shootings in Baghdad, police said on condition of anonymity because they were not supposed to release the information.

Meanwhile, Iraq's foreign minister warned Monday that a quick American troop withdrawal could lead to civil war and the collapse of the Iraqi state, adding that the US has a responsibility to build Iraqi forces so that they take over.

Hoshyar Zebari told reporters that the Iraqis "understand the huge pressure that will increase more and more in the United States" ahead of a September report to Congress by US Ambassador Ryan Crocker and military commander Gen David Petraeus.