The attack took place in an area called Now Dorman on the western outskirts of the the town of Khanaqin near the Iranian border, the official said.

Mahmud Singawi, member of the peshmerga committee in the Kurdish regional government in northern Iraq, said one of those killed was the commander of peshmerga forces in Khanaqin.

"Colonel Zulfiqar was killed by the terrorists in the ambush along with his son Horman who was a lieutenant," Singawi told AFP giving only the first names of the two men.