BAGHDAD -- Iraqi security forces on Sunday launched a new operation to liberate Tal Afar from Islamic State (IS) militants, the Iraqi military said.

The Iraqi army, commandos of the Counter-Terrorism Service (CTS), federal police, paramilitary Hashd Shaabi units and local police are pushing in the rural areas to capture dozens of villages and two districts surrounding the IS stronghold in Tal Afar, some 70 km west of Mosul, Brigadier Mohammed al-Jubouri from the Joint Operations Command told Xinhua.

The troops of three army divisions advanced from the east and the north of Tal Afar, and the CTS commandos advanced from the south, while the federal police and the Hashd Shaabi units initiated a progress from the west of the town, Jubouri said.

During the early hours of the day, the troops, backed by Iraqi and international aircraft, liberated several villages in west and southwest of the town of Tal Afar, and surrounded several others, while other forces took control of four strategic hills in south of the town, according to the first military reports issued by the Hashd Shaabi and the federal police.

The targeted area of Tal Afar is about 3,206 square km, which consists of the town of Tal Afar itself and two districts of Ayadhiyah and Mahalabiyah, in addition to about 47 villages scattered in the area, according to information obtained from the official Iraqiya television.

Tal Afar is the last IS redoubt in the northern Iraqi province of Nineveh. The town and surrounding areas are inhabited by some 350,000 to 400,000 people, including 250,000 people in Tal Afar itself. The majority population of Tal Afar area are Sunni and Shiite Turkomans, in addition to the minority of Kurds and other minorities.

Most of Tal Afar's population left their homes in the town either by the sectarian strife during the years after 2003, or after the town fell to the IS in 2014.

The United Nation's International Organization for Migration (IOM) estimates that some 10,000 to 40,000 people are still living in the town of Tal Afar and surrounding areas.

Earlier, the army's Major General Najim al-Jubouri, commander of Nineveh's Operations Command, told reporters that he estimated there were between 1,500 and 2,000 IS militants left in Tal Afar.

Earlier in the day, Iraqi Prime Minister Haider al-Abadi declared the start of an operation to retake control of the northern town Tal Afar from IS militants.

"We announce the launch of an operation to liberate Tal Afar. I say to Daesh (IS militants) -- either you surrender or die," Abadi said in a televised speech.

"As we announce the start of the operation to liberate Tal Afar we salute the heroic Iraqi forces who fight to bring victory, freedom and peace," Abadi said.