Three US soldiers have been charged with manslaughter in the drowning death of an Iraqi civilian. The man was forced to jump off a bridge into the Tigris River in Baghdad in January, the Army said.

A fourth soldier was charged with assault for ordering a second Iraqi to jump off the bridge. The detainee survived. 

All four soldiers were also yesterday charged with trying to cover up the incident.

The soldiers are assigned to the 3rd Brigade at Fort Carson, Colorado. The brigade is part of the 4th Infantry, based at Fort Hood, Texas.

The new charges come just two weeks after a soldier in the First Armored Division was charged with murder in the shooting death of an Iraqi civilian in May after a high-speed chase in Kufa, south-central Iraq.

The US Army has now opened investigations into the deaths of at least 40 Iraqi detainees, indicating a widening pattern of prisoner abuse, including deaths and assault, beyond the confines of the Abu Ghraib prison near Baghdad.