Ten US soldiers and two Iraqis fighting with the Americans have been killed in an US-Iraqi offensive in the flash point city of Fallujah, Sky News quoted the US military as saying on Tuesday.

On Monday, US Marines, backed by Iraqi troops, started the offensive in a bid to regain the control of the rebel-held city as part of the government's efforts to pacify security situation ahead of the January elections

Fierce battles continued on Tuesday as the US-Iraqi forces thrust into Fallujah. The US Marines, backed by Iraqi forces,raided downtown Fallujah from the northwestern Jolan district andal-Mualemeen district in the east, said witnesses.

On Tuesday, US planes bombed a government clinic in the center of Fallujah, causing dozens of casualties.