Two U.S. Marines were killed by insurgents in restive western Anbar province, the U.S. command said in a statement Monday.
The military said the two Marines, whose identities were withheld pending notification of next of kin, were killed Sunday "due to enemy action." No further details were available.
Two U.S. soldiers had also been killed Sunday by a roadside bomb in east Baghdad.
Their deaths raised to at least 2,441 the number of members of the U.S. military who have died since the beginning of the Iraq war in March 2003, according to an Associated Press count, reports the AP.
The troops of the Southern and Western military districts will begin to return from Russia's southern borders to the points of their permanent deployment starting April 23