A total of 129,642 civilians have fled Mosul and its adjacent districts since military operations to reclaim one of the Islamic State's (IS) last strongholds began in October last year, according to figures released by the International Organisation for Migration (IOM) Tuesday.

Up from 115,242 a week ago, 21,607 families have been forced to flee their homes as a result of over two months of fierce fighting in the city located some 400 km north of the Iraqi capital Baghdad.

Most of the displaced (79 percent) have found refuge in formal camps with the rest finding shelter in private settings, emergency sites and critical shelter arrangements.

Supported by Kurdish Peshmerga fighters, Iraqi troops kicked off operations on Oct. 17, 2016 to recapture the city which fell into IS hands in June 2014 after government forces fled.

While the campaign has slowed in the last few weeks amid gruelling resistance inside the city which has seen extremist militants use civilians as human shields while carrying out brutal counter attacks in small groups moving quickly throughout districts, Iraqi security forces on Sunday extended their grip in the fourth day of a renewed push to retake control of the eastern part of Mosul.

International aircraft as well as Iraqi and U.S.-led coalition artillery units are supporting ground operations there.

According to reports, more than 5,000 IS militants were initially holed up in Mosul.

The UN Refugee Agency (UNHCR) had warned before operations began that as many as 1.2 million people could be forced to flee their homes.