A car bomb blew up yesterday in central Samarra, some 120 km north of Baghdad, killing seven people and wounding two others, police said.

"A car bomb detonated in midday at a patrol of the Iraqi security forces, killing four soldiers and three civilians and wounding two others," said a source from the joint command of the Iraqi police and US troops in Tikrit.

US and Iraqi soldiers cordoned off the blast scene and searched the area for the attackers, the source added.

He also said that four policemen were wounded Thursday morning when insurgents lobbed mortar rounds at a police station in Samarra.

Iraq's interim government is facing a wave of violence by insurgents bent on driving out foreign forces while Iraq's politicians are trying to form a transitional government two months after the parliamentary elections.