Jihadist leaders are fleeing the besieged Iraqi city of Mosul as US-backed local forces close in. The city is the group's last major stronghold in Iraq.
"We are telling Daesh (Arabic acronym for 'IS') that their leaders are abandoning them. We've seen a movement out of Mosul," said US Army Major General Gary Volesky, who heads the land component of the US-led coalitition against the so-called "Islamic State" (IS) group.
Many foreigners among the 3,000 to 4,500 IS fighters would likely end up forming the core of the holdout jihadist force, he added.
As they close in on the city, Iraqi forces have retaken several villages south and east of Mosul, for example Qaraqosh, which lies about 15 kilometres (10 miles) away and was once Iraq's largest Christian town.
They are also reportedly planning multiple assaults for Thursday in what is seen as the largest Iraqi military operation in several years.
Kurdish peshmerga forces are reportedly preparing to attack IS positions on several fronts north of Mosul, while federal forces worked their way up the Tigris Valley.
Can run but can't hide?
Iraqi forces said they may allow fleeing IS fighters an exit to the west in a bid to minimise human and material losses, although Russia's chief of the general staff, Valery Gerasimov, argued it was "necessary not to drive terrorists from one country to the other but to destroy them on the spot."
"It's difficult for them to blend into the local population based on the number of different types of foreign fighters that there are," he said.
"Thousands of desperate Iraqis are fleeing to a filthy and overcrowded Syrian refugee camp in an effort to escape the Mosul offensive," Save The Children said, adding that about 5,000 of them had reached the Al-Hol camp inside Syria near the Iraqi border in the past 10 days.
Tarik Kadir, head of the group's Mosul team, said conditions there are "among the worst we've seen." More than 9,000 people in the camp only have access to dirty, untreated water and have to share 16 latrines, leaving the area polluted by human waste "with a looming risk of disease," the group said.
UN humanitarian chief Stephen O'Brien told the UN Security Council that no large-scale displacement of civilians has been reported since the operation began. But he said the UN anticipates "a displacement wave of some 200,000 people over the coming weeks, with up to one million displaced in the course of the operation in a worst-case scenario."
Iraqi Prime Minister Haider al-Abadi - who announced a broad offensive to retake the city on Monday - visited the front line on Wednesday, as hundreds of thousands of civilians remain trapped in a city with dwindling supplies, many sheltering in basements as air strikes intensified on IS targets.
jbh/jr (AP, AFP)