Iraqi forces have liberated more than 40% of al-Hawija two weeks after the start of the offensive to oust the "Islamic State of Iraq and Syria" (ISIS) from the area, the Al-Hawijah Operations Command said Tuesday (October 3rd).

"Our forces continue to advance in areas occupied by ISIS and to inflict heavy losses on the group," Commander Lt. Gen. Abdul Ameer Rashid Yarallah said at a press conference.

Fifty villages, three towns, al-Rashad district, al-Dheba Airport, Hamrin Mountains and the Allas oilfields have so far been liberated, he said.

"Iraqi forces are now just a few kilometres away from the centre of al-Hawijah," he added.

The UN on Tuesday said an estimated 12,500 people have fled al-Hawija since the launch of the military operation.

"Over the weekend, the number of people who have fled the fighting has increased from 7,000 displaced during the first week of the operation ... to some 12,500 people as of last night," the UN's humanitarian affairs office (OCHA) said in a statement.

"The exact number of people still in al-Hawija is unknown, but could be as high as 78,000," it said.