A roadside bomb blast in western Iraq killed five U.S. Marines on Thursday, the U.S. military said on Friday.
In a statement, the military said the troops from the 2nd Marine Division were in a vehicle in the town of Haqlaniya when they were killed by the explosion.
Roadside bombs are among the deadliest insurgent weapons, but they have rarely killed so many U.S. troops in a single blast.
Since the U.S.-led invasion in March 2003, 1,298 U.S. military and Pentagon personnel have been killed in action in Iraq. Including non-combat deaths the toll is at least 1,690.