Iraqi police officials indicated the crash occured during a firefight between gunmen and Iraqi forces in the area. The U.S. military said hostile fire did not appear to be the cause, though
Also Saturday, the military said itsuspected of masterminding one of the deadliest attacks in Baghdad as well as recent bombings and the 2006 videotaped killing of a Russian official.
The two UH-60 Black Hawks crashed shortly before 9 p.m. in a northern section of the capital known as Azamiyah, the military said. The wounded included two American troops and two other Iraqis, but the total number of people on board was not yet known, a statement said.
"The situation is under control. Emergency services are on the scene," military spokesman Lt. Patrick Evans said. An investigation into the crash was under way.
Two Iraqi police officials, speaking on condition of anonymity because they weren't authorized to release the information, said the crash occurred during clashes between gunmen and U.S.-backed Iraqi forces in northern Baghdad.
Evans denied the reports, saying "we have absolutely no reports of any clashes taking place nearby."
A witness who identified himself only by his nickname Abu Sattar said he was receiving guests in his house when he heard a big explosion.
"We went outside the house and we saw a fire coming from nearby. Then we heard the sounds of gunfire and U.S. soldiers came and sealed off the area," he said.
The U.S. military relies heavily on helicopters to ferry troops, dignitaries and supplies to avoid the threat of ambushes and roadside bombs. At least 70 U.S. helicopters have gone down since the war started in March 2003, according to military figures. Of those, 36 were confirmed to have been shot down.
On Sept. 18, a CH-47 Chinook en route from Kuwait crashed in the southern desert about 60 miles west of Basra on Sept. 18, killing all seven American soldiers on board. The military said that crash apparently was due to a mechanical problem, not hostile fire.