Isis using modified drones to guide suicide bombers and launch ‘airstrikes’.
Iraqi forces secured a series of cautious advances yesterday, pushing into a sprawling military base outside Mosul and on to the grounds of the city's airport, where they took control of the runway.
The three-pronged attack began just after sunrise, with three convoys of Iraqi forces snaking north across Nineveh's hilly desert on Mosul's southern approach.
Iraqi special forces joined federal police and rapid response units in the push - part of a major assault that started this week to drive Isis (Islamic State) from the western half of Iraq's second-largest city. By afternoon they had entered the Ghazlani military base south of the city, as well as the airport.
Iraqi helicopters circled above Mosul firing down on to the city's southwestern edge. Coalition and Iraqi airstrikes that hit targets inside Mosul sent plumes of white smoke into the air on the horizon.
"We've broken the first line of IS defences," said Iraqi special forces Lieutenant Yaser Mohsen, whose troops captured the key village of Tell al-Rayan, where Isis snipers had been slowing the government offensive.
Several coalition armoured vehicles could be seen in the line of military vehicles, and security officials said coalition troops were embedded with the forward advancing forces, advising the Iraqi troops as they conducted the assault. The officials spoke to the Associated Press on condition of anonymity because they were not authorised to talk to reporters.
They then moved to the edge of Mosul's western Mamun neighbourhood, where they were working to surround it before punching into the city.
The cautious advance stood in sharp contrast to the first days of Iraq's push into Mosul from the east, when Iraqi forces quickly advanced deep into the city's congested neighbourhoods, where they were hit with heavy Isis counterattacks, including dozens of car bombs that struck the slow-moving Iraqi convoys with deadly consequences.
On Monday, after weeks of preparations, Iraqi forces launched the operation to take Mosul's western half, with the Iraqi regular army and federal police forces taking part in the initial push. Since then, the military says they have retaken some 120sq km south of the city.
Yesterday marked the first time the Iraqi special forces, which played a key role in securing the eastern half of the city, joined the fight for western Mosul.
A special forces officer overseeing the operation said Isis targeted the advancing troops with dozens of bombs dropped from drones. The officer, who spoke on condition of anonymity because he was not authorised to brief the media, said his troops sustained at least a dozen casualties, including some inflicted by a car bomb attack.
Making up for a lack of fighters, Isis militants are increasingly relying on modified commercial drones to guide suicide car bombers to their targets and to launch small-scale airstrikes on Iraqi forces.
While about 750,000 civilians are estimated to be trapped in Mosul's western sector, only a few dozen could be seen fleeing the city on foot yesterday alongside convoys of Iraqi Humvees.
Hamad Khalaf fled the Mamun neighbourhood in southern Mosul with his wife and four children. Covered in dust, he said Isis fighters were targeting people as they tried to escape.
"There are many injured still inside," he said.
"We've been walking since the morning," said his wife, Badriya, cradling their 18-month-old daughter in her arms. A few metres away a mortar fired from inside the city hit a nearby hill.
In January, Iraqi authorities declared the eastern half of Mosul "fully liberated" from Isis. The battle for western Mosul, the extremist group's last major urban bastion in Iraq, is expected to be the most daunting yet.
The streets are older and narrower in the sector of the city that stretches west from the Tigris River that divides Mosul into its eastern and western halves. The dense urban environment is likely to force Iraqi soldiers to leave the relative safety of their armoured vehicles.
Mosul fell to Isis in the summer of 2014, along with large swathes of northern and western Iraq.