Shiite militias join push to encircle Mosul

State-sanctioned Shiite militias joined Iraq’s Mosul offensive on Saturday with a pre-dawn assault to the west, where they hope to complete the encirclement of the Islamic State-held city and sever supply lines from neighboring Syria.

Other Iraqi forces aided by U.S.-led airstrikes meanwhile drove IS from the town of Shura, south of Mosul, where the militants had rounded up civilians to be used as human shields.

The twin thrusts come nearly two weeks into the offensive to retake Iraq’s second largest city, but most of the fighting is still taking place far from its outskirts, and the entire operation is expected to take weeks.

The involvement of the Iranian-backed Shiite militias has raised concerns that the battle for Mosul, a Sunni-majority city, could aggravate sectarian tensions. Rights groups have accused the militias of abuses against civilians in other Sunni areas retaken from IS, accusations the militia leaders deny.