BAQUBA, Iraq - Insurgents ambushed an Iraqi army patrol north of Baghdad killing 15 soldiers in a well-planned attack.
The attack came a day after the Pentagon announced 10 US Marines were killed by a bomb west of the capital.
The Iraqi soldiers were travelling in a five-vehicle patrol near Baquba, 60km from Baghdad, when they were hit by a roadside bomb. Immediately afterwards, gunmen opened fire in what police described as a well-planned assault.
Hospital officials in Baquba said 15 soldiers were killed and that they were all from southern Iraq where the population is largely Shi'ite Muslim, potentially adding a sectarian element to the attack.
The deaths come amid a rise in insurgent violence ahead of elections set for December 15, and amid growing tensions between Iraq's Muslim sects.
In a move that could aggravate those tensions, the country's top Shi'ite cleric has urged Shi'ites to turn out and vote for religious candidates on election day.
The attack in Baquba, where there has been a surge in guerrilla activity over the past three weeks, followed the assault on the Marines near the former rebel city of Falluja on Thursday, the deadliest attack on US troops for four months.
The Marines were on a foot patrol near a factory when they were struck by a bomb made out of several artillery shells strung together, the Marine Corps said. The deaths raise to more than 2,120 the number of US troops to have died in the war.
US commanders have said they expect an increase in violence in the build up to the election. Over the past three weeks there has a been a series of car bombings and suicide attacks that have killed more than 230 Iraqis, mostly civilians.
Many of the strikes have been sectarian in nature, with Sunni Arab insurgents targeting the Shi'ite majority in an attempt to sow discord and push the country closer to civil war.
Saturday's ambush on the Iraqi troops occurred in Udaim, a volatile town near Baquba, and is the latest in a series of attacks to target Iraq's fledgling police and army forces.
US and Iraqi forces have launched several offensives in the past six weeks throughout Anbar province, a predominantly Sunni Arab region west of Baghdad that is the heartland of the insurgency, to try to create security for the polls.