A member of Iraq's elite Rapid Response Division walks down a street during their advance in western Mosul on April 19, 2017
Mosul (Iraq) (AFP) - Iraqi forces advanced in west Mosul Tuesday, closing in on the Old City where jihadists executed civilians in a desperate bid to prevent an exodus and hold on to their stronghold.
The elite Counter-Terrorism Service retook full control of Tenek -- one of the largest neighbourhoods in west Mosul -- further tightening the noose on the Islamic State group.
"It used to be one of the main strongholds for terrorist groups," Staff Lieutenant General Abdulwahab al-Saadi, a top CTS commander, told AFP in Mosul.
The elite forces have been spearheading a massive offensive launched in mid-October 2016 to retake Mosul, the country's second city and the last major Iraqi bastion of the jihadists' now crumbling "caliphate".
The eastern side of the city, which is divided by the Tigris river, was recaptured in January, and a push on the west bank of Mosul launched the following month has made steady progress despite fierce resistance.
"More than 20 car bombs were destroyed, dozens of terrorist militants were killed. Their bodies are still on the streets and inside houses," said Saadi.
Only a few hundred IS fighters are believed to remain in west Mosul, most of them hunkering down in the Old City among several hundred thousand trapped civilians.
Iraqi forces have retaken neighbourhoods to the south, west and north of the Old City, tightening the noose around IS before a high-risk final assault.
The narrow streets of the Old City and its population density will force the Iraqi forces to conduct perilous dismounted operations which observers fear could yet allow holdout jihadists to stage a protracted last stand.
- Civilians executed -
The use of "human shields" is a key part of the jihadists' defence and on Monday they executed several civilians, in an apparent bid to deter any of them from fleeing or rising up.
IS militants wearing federal police uniforms pretended to be security forces entering an area of the Old City to "liberate" it.
They executed some of the civilians who gave them a hero's welcome, the Joint Operations Command coordinating the war on IS and a local official said.
"Daesh (IS) terrorist gangs committed a brutal crime yesterday," the JOC said, explaining that the jihadists wanted to "confound civilians who expressed joy and welcomed them with chanting".
The JOC statement did not specify how many were killed in that manner but Hossameddin al-Abbar, a member of Nineveh provincial council, told AFP at least 15 civilians were shot dead.
"Daesh members, some of them wearing federal police uniforms, entered the Al-Maidan and Corniche areas of the Old City," he said.
"They were driving black vehicles and posing as liberators from the Iraqi forces," Abbar added. "When some families welcomed them, they arrested several of them. They executed at least 15 other people."
Piling further pressure on the jihadists, Iraqi forces resumed an operation on a separate front southwest of Mosul.
Early on Tuesday, forces from the Hashed al-Shaabi (Popular Mobilisation) paramilitary forces pushed towards the Hatra area, which includes a UN-listed World Heritage site.
- UNESCO site at risk -
The Hashed forces, dominated by Iran-backed militias, 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.
"Hashed al-Shaabi forces launched Operation Mohammed Rasool Allah aimed at liberating Hatra and neighbouring areas," the organisation said in a statement.
It said five villages had already been retaken from IS on Tuesday and that Hashed engineering units were clearing the road to Hatra of explosive devices.
Hatra, known as Al-Hadhr in Arabic, was established in the 3rd or 2nd century BC and became a religious and trading centre under the Parthian empire.
Its imposing fortifications helped it withstand sieges by the forces of two Roman emperors. Hatra finally succumbed to Ardashir I, the founder of the Sassanid dynasty but the city remained well-preserved over the centuries that followed.
The jihadists damaged parts of Hatra after taking over a third of Iraq in 2014, as part of a heritage destruction campaign that also saw them vandalise Mosul museum, blow up shrines and damage the ruins of the ancient city of Nimrud.
The jihadists see such destruction as a religiously mandated elimination of idols -- but they also have no qualms about selling smaller artefacts to fund their operations.
The full extent of the harm to Hatra remains unclear, but the site risks further damage during the military operation to retake it.