ISIL may use chemical weapons and human shields as the advance to retake Mosul continues. Commanders leading the advance say the operation can take months. At the same time, civilians are fleeing the area en masse.

Heavy artillery fire and house-to-house searches. Fighting an estimated five to eight thousand ISIL militants. Joint operations to retake Mosul continue - the U.S. military reports destroying ISIL artillery and mortar systems, rocket and fighting positions and supply caches. The extremists are fighting back using guerilla warfare

"ISIL cannot stay for long, we can catch them wherever we want. We only need time, ISIL cannot stay strong in front of Peshmerga forces, and this is very important," Maj. Gen. Aziz Waisi, commander of Zarvani Peshmergas, said.

ISIL may not stay forever but they will fight unconventionally: possibly using chemical weapons, human shields and booby trapping entire neighborhoods.

There are reports of heavy fighting - Kurdish officials say ISIL blew up at least two buildings in central Mosul and civilians are fleeing the area.

Despite predictions that the current advance could take months, Iraq’s army continues closing in on Mosul, securing more than a dozen villages on the city’s outskirts and capturing ISIL operatives. A top Iraqi military general is calling on ISIL fighters to surrender before it’s too late.