State-sanctioned Shiite militias launched an assault on the Islamic State group west of the Iraqi city of Mosul on Saturday but reiterated that they would not enter the Sunni majority city.
Jaafar al-Husseini, a spokesman for the Hezbollah Brigades, said they launched an offensive Saturday along with other large militias toward the town of Tel Afar, which had a Shiite majority before it fell to IS in 2014. Iranian forces are advising the fighters and Iraqi aircraft are providing airstrikes, he said.
Iraq launched a massive operation to retake militant-held Mosul, its second largest city, last week. The involvement of the Shiite militias has raised concerns the battle could aggravate sectarian divisions.
The Mosul offensive involves more than 25,000 soldiers, Federal Police, Kurdish fighters, Sunni tribesmen and the Shiite militias, which operate under an umbrella organization known as the Popular Mobilization Units.
Many of the militias were originally formed after the 2003 U.S.-led invasion to battle American forces and Sunni insurgents. They were mobilized again and endorsed by the state when IS, a Sunni extremist group, swept through northern and central Iraq in 2014, capturing Mosul and other towns and cities.
A U.S.-led coalition has been providing airstrikes and ground support to Iraqi forces in the Mosul offensive, but al-Husseini said it had no involvement in the Iran-backed militias' advance on Tel Afar.
He said the militias will focus on Tel Afar and on securing the western border with Syria. IS still controls territory on both sides of the border, where it shuttles fighters, weapons and supplies between Mosul and the Syrian city of Raqqa, the de facto capital of its self-styled caliphate.
Iraqi forces advancing toward Mosul from several directions have made uneven progress since the offensive began. Iraqi forces are 4 miles (6 kilometers) from the edge of Mosul on the eastern front, where the elite special forces are leading the charge. But progress has been slower in the south, with Iraqi forces still 20 miles (35 kilometers) from the city.
There have been no major advances over the past two days, as Iraqi forces have sought to consolidate their gains by clearing explosive booby-traps left by the extremists and uncovering tunnels they dug to elude airstrikes.