A transport helicopter crashed in western Iraq on Wednesday, killing 31 US soldiers, CNN reported.

The US military said earlier that a Marine transport helicopter had crashed in the early hours of Wednesday and a search and rescue operation was underway.

The crash occurred shortly after midnight in the western desert close to the Jordanian border, the military said, without giving further details.

In November 2003, two Black Hawks collided and crashed in Mosul after being attacked, killing 17 soldiers.