The fighters were members of the Sinjar Resistance Units, a group founded among the district's Yazidi community in response to a brutal occupation by the Islamic State group nearly a decade ago.

There was no immediate word from the Turkish military, which has conducted deadly strikes against PKK targets in Iraq and neighbouring Syria but rarely comments on individual strikes.

"A Turkish army drone targeted a vehicle of the Sinjar Resistance Units in the region of Wardiya in southern Sinjar, killing an official and a fighter who was escorting him," the counterterrorism services of Iraq's autonomous Kurdish region said in a statement.

Another fighter was injured.

Sinjar and its adjacent mountains are one of the heartlands of Iraq's Yazidi community, a non-Muslim Kurdish speaking minority that was savagely oppressed by IS jihadists when they overran the district in 2014.

The Sinjar Resistance Units were formed in 2014 with help from fellow Kurds of the PKK, which Ankara and its Western allies consider a "terrorist" organisation.

The Sinjar force is also affiliated to the Hashed al-Shaabi, an alliance of mainly Shiite armed groups formed to fight IS and now integrated in the regular Iraqi armed forces.

Turkey frequently carries out ground and air offensives on positions of the PKK -- which has waged a decades-long insurgency against the Turkish state -- in northern Iraq.

It also has over the past 25 years operated several dozen military bases in northern Iraq in its war against the PKK.

On February 20, two civilians were killed in a strike in northern Iraq that was blamed on Turkey, security and health officials said.