The U.S military says the four American helicopters that have crashed in Iraq in the past two weeks were apparently all shot down.
Twenty Americans, including four U.S. civilians, died in the crashes.
It's the first time that the U.S. command has publicly acknowledged that the three Army helicopters and one private security force chopper were probably shot down.
Major General William Caldwell, the chief U.S. military spokesman in Baghdad, told reporters that the investigations into the crashes are incomplete but he said it does appear they were all the result of some kind of, what he referred to as, "anti-Iraqi ground fire."
Caldwell says the effort to target helicopters has been an "ongoing effort" and that adjustments in tactics, techniques and procedures are being made.