By Katherine Sheets, Contributing Writer

Iraqi forces, Kurdish fighters, Sunni Arab tribesmen, Shiite militiamen and a U.S.-led coalition launched an offensive assault against the Islamic State (ISIS)-controlled city of Mosul, Iraq on Oct. 17.

The operation began as Kurdish forces moved in on Mosul from the north and east, the Iraqi army attacked from the south and Shiite militia advanced from the southwest. The BBC reports that in some areas, ISIS is burning tires to reduce visibility while roadblocks and suicide-driver car bombs are attempting to hinder approaches on the city.

Currently, coalition forces are working on capturing surrounding villages, evacuating families and eliminating ISIS militants in the process of advancing on the city.

Iraqi special forces advanced into the town closest to Mosul’s eastern city limits on Monday Oct. 31. According to FOX News, the unit took heavy fire during the dawn attack but was inside and in control of the town of Bazwaya by nightfall. Bazwaya was the last ISIS controlled village outside of Mosul, and the troops were a mere 3 miles outside of the city by the end of the day.

Mosul stands as Iraq’s second largest city and used to be home to over 2 million people. In June 2014, ISIS captured the city, benefitting from its key location in relation to Syria, Turkey and nearby oil fields. According to CNN, gaining control of Mosul from ISIS could significantly limit the movement of the group’s weapons, fighters and supplies.

Politically speaking, ISIS established its caliphate, or Islamic government, shortly after capturing Mosul in 2014. According to the BBC, losing this territorial base would effectively make ISIS less of a governmental threat and more like an insurgency. Mosul is the last large city under ISIS’s control.

Bazwaya was the last ISIS controlled village outside of Mosul, and the troops were a mere 3 miles outside of the city by the end of the day.

One of the biggest challenges of the operation is the civilians. CNN reported that the U.N. is concerned because ISIS took 550 families from villages around Mosul to use as human shields. Ravina Shamdasani, deputy spokeswoman for the U.N. Human Rights Office, told CNN that the families were taken to Mosul in “an apparent policy by ISIS to prevent civilians escaping.” So far, the BBC reports that over 10,000 people have fled their homes with an estimated one million expected to flee. Camps are already being built in preparation for those displaced from the city.

According to FOX News, the continued offensive is estimated to last weeks, if not months. It all depends on the resistance of the estimated five-thousand ISIS militants inside Mosul.