The UN said the number of people escaping from the northern Iraqi city of Mosul has been rising over the past week, as government and allied forces battle deep into the densely populated area in a bid to dislodge so-called "Islamic State" jihadists from their last major stronghold in the country.

According to the United Nations' Office for the Coordination of Humanitarian Affairs, "68,550 people are currently displaced and in need of humanitarian assistance."

The figure, however, falls short of pre-offensive predictions, with the UN initially forecasting that 200,000 civilians could be forced from their homes in the first few weeks of what is Iraq's biggest military operation in years.

The aid challenges posed by the offensive launched against the jihadists on October 17 were growing in complexity, the OCHA said.

"Humanitarian needs are severe among displaced families in and out of camps, vulnerable residents of retaken communities, and people fleeing the intense fighting in Mosul city," it said.

Fighting goes on

Meanwhile, a senior Iraqi commander said on Tuesday that troops were moving to take another neighborhood in the eastern sector of Mosul, but were meeting stiff resistance from IS.

IS fighters were targeting forces with rockets and mortars as the government troops slowly advanced in the densely populated al-Zohour neighborhood, Brigadier General Haider Fadel of the special forces told The Associated Press. "They are cautiously advancing," he said.

Most gains have been made by the special forces operating east of the Tigris River. Other forces are advancing on the city from different directions, while the US-led coalition provides airstrikes and other support.

Mosul, Iraq's second city, was captured by the extremist group IS in the summer of 2014.

jbh/tj (AFP, AP)