Updated

Six U.S. service members were killed in a mortar attack Sunday in western Iraq the U.S. military said.

A military spokeswoman gave no further details and did not say whether the victims were Marines or Army soldiers.

The attack occurred in Anbar province, which includes such flashpoint cities as Fallujah (search) and Ramadi in the Sunni Triangle, a hotbed of resistance.

The deaths raised the U.S. death toll to 151 since a wave of violence began on April 1. At least 753 U.S. troops have died in Iraq since the war began in March 2003.