Iraqi security forces say they recaptured six districts in Mosul's east on Friday despite a fierce ISIL counter attack. As the fighting intensified, so too did the number of people attempting to flee the city.

Iraqi forces say they are now in control of six neighborhoods in Mosul, having inflicted heavy losses on ISIL. Though witnesses say a fierce counter attack by the extremist fighters had pushed back some units.The battle raged as the United Nations accused ISIL of murdering civilians and even its own members.

"We also continue to receive reports of mass killings, including one incident on Monday, when ISIL reportedly killed 50 of its own militants, in the Ghazlani military base in Mosul city, for alleged desertion," said Ravina Shamdasani, spokeswoman, UN Office of the High Commissioner for Human Rights.

"There are also credible reports that 180 people were killed on Wednesday, in Kokjali town, in eastern Mosul... And possibly up to another 200 people were killed in Mosul city."

The Iraqi army, Kurdish Peshmerga and Militias have now almost encircled the city.

A wide range of militias are fighting ISIL outside or on the edge of Mosul but only Iraqi state forces are allowed incide the city, all part of the government's attemp to keep sectarian politics away from the main battlefield.

Thousands of Iraqis displaced by the fighting have found shelter in the newly established Khazir refugee camp just outside the city.

"For the time being we have enough food to feed about one million people for a month," said Inger Marie Vennize, Head of External Relations of World Food Program.

Many who fled Mosul have been reunited with relatives for the first time since ISIL captured the city in 2014.

"This is my family, these are my people, I cannot describe the feeling, even my voice fails me, I've lost my voice. I have not seen them for two years and a half," said Ziyad Ezz-Eldin, internally displaced man.

The United Nations says 22,000 people have been displaced since the start of the Mosul campaign, but has warned the number could rise as high as one million.