Six Iraqi civilians were killed and 13 others wounded in a roadside bomb blast in southwestern Baghdad on Sunday, an Interior Ministry source told Xinhua.

"An explosive charge detonated near civilian cars on the main road near Um al-Tubol mosque, killing six civilians and wounding 13 others," the source said on condition of anonymity.

It was not clear what was the target of the attack as there was no U.S. or Iraqi security forces at the scene, he said.

Roadside bombs have become a major killer of U.S. and Iraqi forces in the bloody insurgency in Iraq.

Source: Xinhua