Iraqi forces on Sunday launched an operation to recapture Mosul's Old City, the last ISIL stronghold in the northern city, a top Iraqi commander announced.

In a statement, Lt. Gen. Abdul-Amir Rasheed Yar Allah, the commander of army operations in Ninevah province, said army troops, anti-terror forces and federal police are taking part in the operation.

The Old City is the last area still under ISIL control in Mosul, once Iraq's second largest city in terms of population.

It is a densely-populated maze of narrow alleyways where fighting is often done house by house.

Iraqi forces, backed by air cover from a U.S.-led coalition, are currently engaged in a widespread offensive to dislodge ISIL from Mosul, the terrorist group’s last stronghold in Iraq.