Iraqi special forces have moved more than 1,000 people from villages near the front lines of the battle to retake the ISIS-held city of Mosul.

Special forces Maj Gen Haider Fadhil says the residents of Tob Zawa and other nearby villages have been taken to a camp in the nearby Khazer region for their safety.

The International Organisation for Migration says at least 8,940 people have been displaced since the operation to retake Mosul began on October 17.

Maj Salam al-Obeidi says the special forces were undertaking clean up operations on Wednesday in areas retaken from the militants to the east of the city.

He says troops had uncovered a vast tunnel network used by ISIS to shuttle fighters and supplies by motorcycle.