Four U.S. Marines (search) were killed in a vehicle accident while conducting security operations in an area of western Iraq that has been a hotbed of anti-American resistance, the U.S. command said Sunday.

The Marines were killed Saturday in Anbar (search), a Sunni-dominated area west of the Iraqi capital that includes the cities of Fallujah, Ramadi and Qaim on the Syrian border.

They were assigned to the 1st Marine Expeditionary Force (search).

The military withheld the names of the victims pending notification of their families.

More than 875 service members have died since the beginning of military operations in Iraq last year, according to the U.S. Defense Department.