London: Western-backed Iraqi forces are capturing some Islamic State fighters as they fight to liberate Mosul and Raqqa but the vast majority of foreign fighters are "fighting to the death", the US-led coalition for the fight against IS said.
Colonel John Dorrian, the spokesperson for the global coalition against IS said just 1000 remain in Mosul, Iraq while between 3000-4000 are still fighting in Raqqa.
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Colonel Dorrian said the Iraqis had "taken control" of some foreign fighters captured in Mosul but declined to specify how many or from which countries. He also declined to say how many overall IS fighters had been captured.
He said that by the end of the military campaign to liberate Mosul "every single ISIS fighter that's left in Mosul is either going to be killed or going to be surrender", but said captures were rare.
"We're not seeing a tremendous number of those because a lot of the foreign fighters are very hardcore and they came here to die," he told international journalists in London via a video conference call from Baghdad.
"They're not surrendering, they're fighting to the death," he said. The Guardian cited senior IS figures admitting they were crumbling and large numbers of jihadists were abandoning the battlefield and trying to escape, including surrendering via Turkey.
Colonel Dorrian said IS' leadership preferred to leave embattled territory and leave foreign fighters behind to carry out chemical attacks against civilians. "These are the types of things that are very easy to do when it's not your neighbours or people you've grown up with or know very well," he said.
The federal government has said that "up to" 110 Australians are currently fighting in the conflict in Iraq and Syria, with a further 70 killed.

"We do make up a reasonable, sizeable chunk of the western foreign fighters that have gone into this conflict," Justice Minister Michael Keenan said.
The ABC on Thursday reported Turkey has placed more than 400 Australians on its terrorism watch list. Turkey was the gateway for jihadists seeking to join Islamic State in its peak in 2014-15 when it declared a caliphate across parts of the Middle East, before it began cracking down on the flow of foreign fighters.

Coalition forces had hoped to liberate Mosul by the spring but declined to put a timeframe on when liberation might be expected.