Four U.S. soldiers were killed when their vehicle was run over by an Iraqi truck outside Iraq's western flashpoint city of Fallujah early on Saturday, a police source told Xinhua.

"An Iraqi truck ran over a US Humvee parking near a checkpoint at the southern entrance of Fallujah, killing four U.S. soldiers aboard," the source said on condition of anonymity.

It was not clear whether the Iraqi truck driver premeditatedly hit the US Humvee, the source added.

The US military did not confirm the incident yet.

The Sunni-dominated Fallujah, some 50 km west of Baghdad, has witnessed sporadic insurgent attacks against the U.S. and Iraqi government forces despite U.S.-Iraqi military operations in the city to stem out violence.

Source: Xinhua