A bomb exploded outside a Shiite mosque in northern Baghdad on Tuesday evening, killing at least 11 people and injuring seven others, police said.

The blast occurred in Baghdad's Tunis district and most of the casualties were prayers, the source told Xinhua.

The source said the blast was likely triggered by a motorcycle bomb since debris of a motorcycle was found at the scene.

Earlier in the day, five people were killed and 13 others injured when a car bomb went off in Sadr City, a Shiite-dominated neighborhood in eastern Baghdad.

(Xinhua News Agency May 24, 2006)