Smoke billows as Iraqi forces attack Mosul airport during an offensive to retake the western side of the city from jihadists of the Islamic State group on February 23, 2017. (AFP photo)

MOSUL, Iraq, Feb. 23 (Xinhua) -- Iraqi security forces on Thursday retook control of Mosul international airport after heavy clashes with Islamic State (IS) militants, a security source said.

Federal police and elite interior ministry units, known as Rapid Response, have completely liberated the airport in southern Mosul after several hours of fierce clashes with the IS militants, Lt. Gen. Raid Shakir Jawdat, the commander of the federal police forces, told Xinhua.

The troops also freed the adjacent compound of a sugar plant and its residential buildings, Jawdat said.

The battles in the perimeter and airport left 30 IS militants killed and dozens of others wounded, in addition to arresting 20 militants, including non-Iraqi Arabs and foreigners, Jawdat said.

The airport facilities and runway were badly damaged, as the extremist militants bombed all the buildings before they withdrew, he added.

Meanwhile, the Counter-Terrorism Service (CTS) special forces seized part of Ghazlani military base near the airport after heavy battles with the extremist militants, a security source told Xinhua on condition of anonymity.

In the morning, Lt. Gen. Abdul-Amir Yarallah, from the Joint Operations Command, announced in a statement the start of an assault to retake control of Mosul's international airport and a military base nearby from IS militant group.

The attacks on Thursday came as Iraqi security forces advance toward the fringes of the western side of Mosul to drive out IS militants from their last major stronghold in Iraq.

Iraqi Prime Minister Haider al-Abadi, who is also the commander-in-chief of the armed forces, announced on Sunday the start of an offensive to drive extremist militants out of the western side of Mosul, locally known as the right bank of Tigris River, which bisects the city.

Late in January, Abadi declared the liberation of the eastern side of Mosul, or the left bank of Tigris, after more than 100 days of fighting against IS militants.

However, the western side of Mosul, with its narrow streets and a population of between 750,000 and 800,000, appears to be a bigger challenge to the Iraqi forces.

Mosul, 400 km north of the Iraqi capital of Baghdad, has been under IS control since June 2014, when Iraqi government forces abandoned their weapons and fled, enabling IS militants to take control of parts of Iraq's northern and western regions.