On the Mosul front lines, Iraqi forces have found a new tool to counter the Islamic State group's suicide car bombs: small commercial drones.

"It's a car bomb!" Mohammed Salih alerted his forces after checking the live feed from a drone his men were flying over the area, on the Mosul battle's southern front.

A few seconds later, a large plume of smoke rose up where an attack helicopter had fired two rockets and taken out the explosives-laden vehicle that was heading straight for his men.

The dust had not yet settled when another threat materialised on the drone's monitor.

"There are four Daesh (IS) members on your right-hand side. They are not friendlies, repeat, not friendlies," Salih said.

Men of the Iraqi army's 15th division were advancing through Salahiyah village, on the edge of Hamam al-Alil, one of the main targets on the vast southern front.

The drone flew over enemy lines and landed back on the roof of the village school, which sits atop a hill overlooking the plain and has been turned into a temporary command centre.

"This drone allows us to reconnoitre the area, spot the enemy's movements and direct our soldiers more efficiently towards their targets so we can destroy them," Salih said.

The toy-like device is barely wider than a foot and is available in shops or online for around $600, or less than the latest iPhone.

It has a camera, four rotors and is guided with a joystick connected to a tablet that feeds images that can be shot from an altitude of more than 150 metres (500 feet).

IS fighters use snipers and mortars when Iraqi forces approach their positions, but when both sides engage on the ground, the jihadists' weapon of choice is the suicide car bomb.

- 'Not real men' -

They have unleashed dozens of them every week since the start of the offensive against Mosul on October 17, inflicting casualties on Iraqi forces although the authorities have not provided any figures.

"Some of them fight and die but others run away -- these are not real men," Ali, a 25-year-old fighter from the division's commando unit, said.

He thumbed bullets into six magazines for his M-16 assault rifle. "I'm determined to use all of them and I have more in stock," he said with a grin.

Ali's mood changed when he pulled up a picture of a smiling young man on his mobile phone.

"He was my friend. The day before yesterday, they blew up his Humvee with a guided missile. He burned to death inside the vehicle," he said.

The 15th division moved towards Hamam al-Ali, despite intensifying fire from IS and the seemingly endless detonations of roadside bombs.

Helicopters flying overhead fired missiles at IS positions dozens of times to open the way for army convoys.

The first wounded soldier was brought in with a hole in each thigh from the same bullet, his own blood running down his rifle barrel.

The drone's latest information was inconclusive: were the men spotted about 600 metres (yards) from the village mosque IS militants or his own fighters?

"We need to check this out," Salih said, walking over to the site with his red beret but no protective gear.

His left elbow still had pins sticking out of it, following a wound sustained during a previous battle.

The streets of Salahiyah were too narrow for two vehicles to cross, some roofs had collapsed and the ground was carpeted with bullet casings.

In the deserted village, the explosions ebbed and eventually stopped with nightfall. The area was now under government control.

"The next move is Hamam al-Alil and then Mosul," Salih trumpeted, to cheers from his men who vowed to follow him "right to the heart of Daesh".