Eight US soldiers were killed when their Black Hawk helicopter made an "emergency landing" just south of Fallujah, Iraq, CNN quoted military sources as saying on Thursday.

It was the latest in several fatal chopper crashes, and the third in the Fallujah area since November.

The UH-60 Black Hawk had a crew of four and was carrying four passengers.

The cause of the incident, which took place at 1400 hours (local time), was not clear

The 82nd Airborne Division is in charge of operations in the region.