Up to 20,000 civilians trapped in Mosul amid Islamic State's last stand

As many as 20,000 civilians are trapped in the last areas controlled by the Islamic State group in Mosul's Old City, which Iraqi forces are battling to retake, a senior UN official said on Thursday.

More than eight months since the start of the operation to retake Mosul from IS, the militants have gone from fully controlling the city to holding a small pocket of territory on the west bank of the Tigris River.

But the fighting against the last IS holdouts is intense, and civilians caught in the middle of the battle are in "extreme danger," UN humanitarian coordinator in Iraq, Lise Grande, told AFP.

"The people that are still trapped inside of these pockets are in terrible condition," facing shortages of food, she said.

"They're in extreme danger from bombardment, from artillery crossfire. The (IS) fighters that are still there are still directly targeting civilians if they try and leave."

The battle has taken a heavy toll on civilians, nearly 700,000 of whom are currently displaced as a result of the fighting, she said.

Desperate stand

IS militants are increasingly using suicide bombers in a desperate attempt to slow the steady advance of Iraqi forces, military commanders said on Thursday.

Iraqi forces pushing towards the al-Maydan and al-Shareen districts in the northern Iraqi city broke the militants' defences and have reached within 200 metres of the riverbank.

But they encountered stiff resistance from a few hundred militants lodged among thousands of civilians in the Old City's maze of alleyways, particularly from foreign suicide bombers, Iraqi commanders said.

The military has predicted final victory this week after a grinding eight-month assault to oust IS from the once two-million-strong city.

Lieutenant General Sami Aridhi of the elite counter-terrorism service said the militants were increasingly detonating explosives among civilians fleeing towards security forces and had even resorted to using women suicide bombers.

"They have begun to wait for the troops to reach them and then blow themselves up. They can't do any more than that," he told state television.

"They surge forward just to obstruct the troops, not to hold land or retain any other positions because God willing their end is clear to everyone and they are convinced that this is their end," he said.