Drones struck oilfields in Iraqi Kurdistan on Thursday, with officials pointing to Iran-backed militias as the likely source of attacks this week that have slashed the region's oil output by more than half.

BAGHDAD (Reuters) -A drone attack targeted an oilfield operated by Norwegian oil and gas firm DNO in Tawke, in the Zakho Administration area of northern Iraq, on Thursday, the Kurdistan region's counter-terrorism service said. The attack is the second on the DNO-operated field since a wave of drone attacks began early this week.

Drones targeted oil fields in Iraq’s semi-autonomous northern Kurdish region Wednesday, the latest in a series of attacks in recent days that have put several oil facilities out of commission. No group has claimed responsibility for the attacks,