IS chief Abu Bakr al-Baghdadi is reported to have abandoned Mosul, leaving local commanders behind to lead the battle against Iraqi forces advancing in the city.

With Iraqi troops making steady progress in their assault to retake Mosul from the jihadists, a USinfo-icon defence official said Baghdadi had fled to avoid being trapped inside.

It was the latest sign that IS is feeling the pressure from twin US-backed offensives that have seen it lose much of the territory it once controlled in Iraqinfo-icon and Syriainfo-icon.Speaking to reporters in Washington, the defence official said Baghdadi had left Mosul before Iraqi forces seized control of a key road at the beginning of this month, isolating the jihadists in the city. "He was in Mosul at some point before the offensive ... He left before we isolated Mosul and Tal Afar," a town to the west, the official said. "He probably gave broad strategic guidance and has left it to battlefield commanders."

Baghdadi, who declared IS's cross-border "caliphate" at a Mosul mosque in 2014, in an audio message in November urged supporters to make a stand in the city rather than "retreating in shame".In recent days Iraqi forces have retaken a series of neighbourhoods in west Mosul as well as the provincial government headquarters and a museum where IS militants filmed themselves destroying priceless artefacts.

On Thursday Iraqi forces were "combing the city centre area to defuse [bombs in] homes and shops and buildings," said Lieutenant Colonel Abdulamir al-Mohammedawi of Iraq's elite Rapid Response Division.The area is located on the edge of Mosul's Old City, a warren of narrow streets and closely spaced houses that could see some of the toughest fighting of the battle.

"Currently there is no order from the operations command to advance toward the Old City. We will advance when this order is issued," Mohammedawi said.Hundreds of thousands of civilians are believed to still be trapped under IS rule in Mosul.Those who did manage to escape the city said the jihadists were growing increasingly desperate.

"We were used as human shields," said Abdulrazzaq Ahmed, a 25-year-old civil servant, who escaped along with hundreds of other civilians to Iraqi police waiting outside the city.Rayan Mohammed, a frail 18-year-old who was once given 60 lashes for missing prayers, said the jihadists were scrambling in the face of the Iraqi offensive."They ran away like chickens," he said. 

Wedding party suicide attack 

Even with the territory they control greatly reduced, the jihadists remain a major threat.

At least 26 people were killed late on Wednesday when two suicide bombers attacked a celebration being held the night before a wedding north of Baghdad, Iraqi officials said.The bombings in the Al-Hajaj area, north of the city of Tikrit, also wounded 25 people.

There was no immediate claim of responsibility for the attack, but IS carries out frequent suicide bombings targeting both civilians and members of the security forces in Iraq.