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,

A drone attack halted production at the Sarsang oilfield in Iraq’s Kurdistan region on Tuesday only hours before its U.S. operator signed a deal to develop another field.

Several oilfields operated by foreign companies in Iraq’s semi-autonomous region of Kurdistan have halted production in the past few hours following attacks with explosive-laden drones on infrastructure at the fields.