Iraqi forces on Friday took control of the last district in the oil-rich province of Kirkuk that was still in the hands of Kurdish peshmerga fighters, security sources said.

The district of Altun Kupri, or Perde in Kurdish, lies on the road between the city of Kirkuk — which fell to Iraqi forces on Monday — and Irbil, capital of the semi-autonomous northern Iraqi region of Kurdistan, which voted in a referendum last month to secede from Iraq.

A force made up of U.S.-trained Iraqi Counter-Terrorism Service units, Federal Police and Iranian-backed fighters known as Popular Mobilization began their advance on Altun Kupri at 7:30 a.m., said an Iraqi military spokesman.