"No activity fire was observed in the area at that time," a U.S. statement said, adding that the crash was under investigation.

There was no further information on the cause of the crash or the exact location.

The province of Salahaddin, whose capital is Saddam Hussein's hometown of Tikrit, was put under curfew on Sunday morning to avoid violence sparked by the death sentence issued against the former Iraqi president on Sunday.

Earlier on Monday the military said two marines and a soldier were killed at the weekend in the western Anbar province, where U.S. forces are battling Sunni insurgents that include al Qaeda Islamists.

The latest deaths brought the total American military death toll since the invasion of March 2003 to 2,836.

In October, 105 deaths were the highest monthly toll in nearly two years, drawing renewed attention to the losses in the middle of campaigning for elections that could cost U.S. President George W. Bush's Republicans control of Congress.

November 6, 2006