Militants set up a fake checkpoint in western Iraq and ambushed a convoy of 14 border policemen on Wednesday, killing all of them and setting fire to the bodies of two of them, officials said.
The checkpoint was set up along the main highway connecting Iraq to Saudi Arabia, with the attack taking place near the town of Nukhaib.
At about 11:00 am (0800 GMT), the men were travelling along the highway in three unmarked cars to begin their shifts at various checkpoints, Major General Yasir Assem from the border guards said.
They were stopped at the fake checkpoint and gunned down, and two of their bodies set on fire.
A medic at the clinic in Nukhaib, about 200 kilometres (125 miles) west of the Shiite shrine city of Karbala, confirmed the toll.
Nukhaib is in Anbar province, but is part of a tract of land claimed by neighbouring Karbala province.
It was the site of a brutal attack in September 2011 that sent tensions soaring between the two provinces. Militants killed 22 Shiite pilgrims from Karbala aboard a bus bound for Syria.
Anbar province has long been a stronghold of Sunni militants, including those linked to Al-Qaeda.
Many tribal militias turned against Al-Qaeda and joined forces with the US military from late-2006, but they have failed to completely eliminate such attacks, which often target the security forces in a bid to undermine confidence in the authorities.
Violence has been on the rise in recent months, with the number of people killed in May the highest since 2008. However, overall deaths remain far below levels registered during the brutal 2006-2007 sectarian war.