Iraqi forces prepared today to retake several key areas around Mosul, including the country's largest Christian town, to tighten the noose on the Islamic State group's stronghold.
Kurdish and federal troops have made quick progress since the offensive was launched on Monday but officials have cautioned that Iraq's largest military operation in years could last months.
Hundreds of thousands of civilians were still trapped in the city with dwindling supplies, many sheltering in basements as air strikes intensified on IS targets.
"We couldn't sleep last night because of the air strikes. The explosions were huge but I'm not sure what the targets were," said Abu Saif, a 47-year-old resident contacted by AFP.
"Many families are starting to run out of some basic food goods, there is no commercial activity in Mosul -- the city is cut off from the world," he said.
East of Mosul, forces were poised for an assault on Qaraqosh, which lies about 15 kilometres and was once Iraq's largest Christian town.
News of the move to recapture Qaraqosh sparked jubilation among Christians who had fled the town, with many dancing and singing in the city of Arbil last night.
Units from Iraq's elite counter-terrorism service, which has done the heavy lifting in most recent operations against IS, were poised to flush jihadists out of the town on Wednesday, officers said.
"We are surrounding Hamdaniya now," Lieutenant General Riyadh Tawfiq, commander of Iraq's ground forces, told AFP at the main staging base of Qayyarah, referring to the district that includes Qaraqosh.
"There are some pockets (of resistance), some clashes, they send car bombs -- but it will not help them," he said.
Qaraqosh was the largest of many Christian towns and villages seized by the jihadists who swept across the Nineveh Plain east of Mosul in August 2014.
The mass exodus it sparked displaced a large proportion of Iraq's already dwindling Christian minority, sending most into the neighbouring Kurdish region.
Qaraqosh was home to around 50,000 people in 2014 and has at least seven churches, making it a key hub for the more than 300,000 Christians still in Iraq.
Kurdish peshmerga forces prepared to attack IS positions on several fronts north of Mosul while federal forces worked their way up the Tigris Valley.
Some families recovering their freedom from IS for the first time in more than two years cautiously approached security forces waving white flags.
In one village in the Al-Shura district south of Mosul, the men were promptly isolated and herded into a handful of buildings for screening.
The families were being dispatched to various temporary camps, including near Qayyarah.
The "caliphate" that IS leader Abu Bakr al-Baghdadi proclaimed in Mosul's Great Mosque in June 2014 once covered more than a third of Iraq and parts of Syria.
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But it has been shrinking steadily for more than a year and retaking Mosul would be a major setback for IS, all but ending its experiment in statehood.
"IS simply has too many enemies with the world arrayed against it," said Aymenn al-Tamimi, a jihadism expert at the Middle East Forum.
Tens of thousands of personnel are involved in the operation to retake Mosul, where the jihadists have an estimated 3,000 to 4,500 fighters.
World leaders and military commanders warned that -- despite signs that early progress in the Mosul offensive was faster than predicted -- the battle could be long and difficult.
"Mosul will be a difficult fight. There will be advances and there will be setbacks," Obama said yesterday.
After clearing towns and villages on the outskirts of Mosul with air support from a US-led coalition, Iraqi forces are expected to besiege the city before entering it.
Iraqi forces may allow fleeing IS fighters an exit to the west in a bid to minimise human and material losses from the fighting inside the city.
But the chief of Russia's 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".
Russia, he said, was focusing on "possible attempts by fighters to break out of Mosul" and "freely leave the city in the direction of Syria".
Many civilians have been able to flee the wider Mosul region to safer areas, with some desperate enough to seek refuge over the border in war-torn Syria.
"Thousands of desperate Iraqis are fleeing to a filthy and overcrowded Syrian refugee camp in an effort to escape the Mosul offensive," the Save The Children aid group said.
It said about 5,000 of them had reached the Al-Hol camp in the past 10 days.