Mosul offensive: Elite special forces deployed as Iraqi prime minister says attack ‘advancing faster than expected’

In some places the US-backed Iraqi coalition is just four miles away from outskirts of Isis-held city following three days of heavy fighting

The long-anticipated offensive to free the city of Mosul from Isis is going faster than planned, Iraqi prime minister Haider al-Abadi has said, as the country's elite special forces were deployed in the fight for the first time.

“The forces are pushing towards the town more quickly than we thought and more quickly than we had programmed,” Mr al-Abadi said via satlink to representatives of several Middle Eastern and Western countries gathered in Paris on Thursday to discuss Iraq’s future.

As day four of the offensive dawned, the elite Counter Terrorism Service (CTS) drove black Humvees mounted with machine guns towards the deserted town of Bartella, east of the city, one of the main bases from which the multi-sided attack will be launched. Think plumes of black smoke rose into the air above the Ninevah plains, likely from oil fires started by Isis to make targeting more difficult.

Isis used suicide car bombers, as well as mortar fire, snipers and roadside mines to try and slow the advance, in a move a US military official in Baghdad said showed the group’s desperation.

Suicide bombers used in retreat “reinforces the point that they are completely on the defensive and are just trying to hold on,” Maj. Gen. Gary J. Volesky said.

“Bartella is the eastern gate of Mosul,” a CTS spokesperson said. The elite US-trained force planned to capitalise on the experience gained in spearheading most of the successful advances against Isis so far, including freeing the southern city of Fallujah, he added.

The CTS units are deployed on a Kurdish front line, marking the first joint military operation between the government of Baghdad and the autonomous Kurdish Regional Government based in Irbil in the north of the country.

Several highly trained army units also moved to a position to the north of the city on Wednesday night. The Iraqi army and allied Kurdish forces have made steady gains to the south and east clearing villages of Isis militants since Monday’s announcement the start of the operation to retake the city - ruled by Isis for two years - had begun. In some places, the frontline is now just four miles (nine kilometres) away.

Mosul is Isis’ last stronghold in Iraq, but they are unwilling to surrender it without a fight. Over the last two years, the group has dug an extensive network of tunnels to transport equipment and fighters, and prepared for battle by rigging roads and bridges with bombs and digging trenches to be filled with burning oil to impede the Iraqi forces’ movements.

The city’s estimated population of 1.5 million people is in danger of being caught in the crossfire, several aid agencies have warned, or being used as human shields. The UN and several other charities are also woefully ill-prepared to deal with an expected exodus of 200,000 - 700,000 people when fighting reaches the city proper because of major funding shortages.

The battle is expected to last weeks or months, marking the biggest military operation in Iraq since the US invasion of 2003 - 2011.

The future of the multi-ethnic city has implications for wider Iraq, as Shia militia, Sunni tribal fighters, Kurdish peshmerga forces and the army - all with complex and conflicting interests - are expected to struggle for control in the aftermath of the fighting.

How to govern Mosul sustainably while avoiding any opportunities for violence along sectarian lines is on the agenda for the Iraqi officials and world leaders meeting in Paris on Thursday.