A U.S. Marine transport helicopter crashed early on Wednesday in western Iraq, the U.S. military said in a statement.
It said a search and rescue operation was under way. The statement said casualties would be confirmed later.
The military said the crash happened shortly after midnight in the western desert close to the &to=http:// english.pravda.ru/main/2003/04/01/45392.html ' target=_blank>Jordanian border, but it gave no details on the cause.
Some of the deadliest incidents for U.S. forces in the Iraq war have been helicopter crashes.
In November 2003, two Black Hawks collided and crashed in Mosul after coming under fire, and 17 soldiers were killed.
Earlier the same month, a &to=http:// english.pravda.ru/world/2003/03/12/44261.html ' target=_blank>Chinook was shot down by insurgents in western Iraq, killing 16 U.S. troops, informs Reuters.
According to BBC News, the aircraft, transporting personnel from the 1st Marine Division, came down near Rutbah, close to the border with Jordan, at about 0120 (2220 GMT).
The cause of the crash is unknown and the military has not yet provided casualty figures.
Meanwhile, in Baquba, north of Baghdad, insurgents attacked party political offices ahead of Sunday's election.
At least one policeman was killed as rebels hit the premises of the Communist Party and the &to=http:// english.pravda.ru/main/2002/12/19/41041.html ' target=_blank>Patriotic Union of Kurdistan with heavy machine gun fire, officials said.
Militants have vowed to disrupt the election on Sunday, and have already launched numerous attacks on political figures, security forces and designated polling stations.
Become a member of Pravda.ru online community