BAGHDAD: Iraqi troops Tuesday drove out Daesh (ISIS) militants from the largest neighborhood in the western half of the city of Mosul, a senior military commander said, a major development in the monthslong fight to recapture the country’s second-largest city. Elsewhere, Popular Mobilization forces launched a fresh push southwest of Mosul to retake the Hatra area, which includes a U.N.-listed World Heritage site, a statement said.

The operation marks the latest phase of an offensive launched by the paramilitary forces in parallel to the main assault on Mosul begun six months ago.

U.S.-backed Iraqi forces declared eastern Mosul “fully liberated” in January, after officially launching the operation to retake the city in October. In February, the troops started a new push to clear Mosul’s western side of Daesh militants, but weeks later their push stalled mainly due to stiff resistance by the militant group.

Tuesday, special forces Lt. Gen. Abdel-Wahab al-Saadi told the Associated Press that the sprawling Al-Tanek neighborhood was now “fully liberated and under full control” of the security forces. Saadi did not provide more details.

To the east of Al-Tanek, Iraqi forces have been facing tough resistance from Daesh in Mosul’s Old City, an area that stretches along the Tigris River, which divides Mosul into its eastern and western halves. The Old City’s narrow alleys and densely populated areas have made it hard for troops to move forward.

Monday, Daesh militants posing as liberating security forces killed at least 15 civilians who welcomed them in central Mosul, officials said.

Wearing police uniforms, they entered parts of the Old City to trick residents into showing their support for the federal forces, the Joint Operations Command and a local official said in a statement. It said the militants wanted to “confound civilians who expressed joy and welcomed them with chanting.”

Hossameddin al-Abbar, a member of the Ninevah provincial council, told AFP that when some families welcomed them, Daesh members arrested several of them and shot dead 15 others.

They killed women and children, the JOC said, “to make it clear the area was still under enemy control.”

Also Tuesday, the government-sanctioned paramilitary troops, made up mainly of Shiite militiamen, launched a new push to retake the town of Hatra to the south of Mosul. The force’s spokesman, Ahmed al-Asadi, said the operation is being conducted from three directions with aerial support from the Iraqi Air Force. Asadi did not elaborate.

The Popular Mobilization forces have focused their efforts on a front southwest of Mosul which aims at retaking the town of Tal Afar as well as desert areas stretching to the border with Syria.

“[The Popular Mobilization] forces launched Operation Mohammad Rasool Allah aimed at liberating Hatra and neighboring areas,” the organization said in a statement.

It said that five villages had already been retaken from Daesh Tuesday and that the Popular Mobilization engineering units were clearing the road to Hatra of explosive devices.

Hatra, known as Al-Hadhr in Arabic, is home to a UNESCO World Heritage site of the same name that was destroyed by Daesh as part of the militants’ efforts to demolish archaeological sites in and around Mosul. The militants consider the priceless archaeological treasures – some dating back as far as 3000 B.C. – as idolatry but have at the same time smuggled and sold many looted artifacts to fund their war.