Iraqi police and witnesses say at least 10 civilians were killed during a raid on an apartment building in southern Baghdad.

A man who lives in the area says he was awakened by the sound of helicopters, heavy gunfire and bombing. A police officer says an unknown number of people also were detained after the incident, which involved clashes between U.S. helicopters and gunmen.

The U.S. military says it is checking into the report.

In violence north of Baghdad, authorities say at least six people were killed yesterday when four gunmen with long beards wearing military uniforms barged into a busy cafe.