Shiite fighters from the Hashed al-Shaabi (Popular Mobilisation) advance from an area near Qayyarah towards the village of Tal Um Jadaan, southwest of Mosul, on November 26, 2016, during an ongoing operation against Islamic State (IS) group jihadists. (AFP/Xinhua)

MOSUL, Iraq, Nov. 28 (Xinhua) -- Iraqi security forces in Monday continued their clashes against the Islamic State (IS) militants and seized more ground in and near the city of Mosul, after nearly six weeks since a major offensive was launched to drive out the extremist militants from their last major stronghold in the country, the Iraqi military said.

In eastern Mosul, the commandos of the Counter-Terrorism Service (CTS) fought heavy clashes with the IS militants and managed to completely clear the districts of al-Qahira, Masarif and Amin, a statement by the Iraqi Joint Operations Command (JOC) said.

The number of districts that have been completely freed by the CTS commandos reached so far 23, the statement said.

The troops inside Mosul have met stubborn resistance from the extremist militants, who are fighting in small groups and moving quickly throughout the districts in the eastern side of the city, locally named the left bank of the Tigris River that bisects the city.

The extremist groups frequently infiltrated behind the advanced CTS forces using tunnels or sneaking through dozens of houses and buildings.

In southeast of Mosul, the Iraqi army freed the villages of al-Gaser and al-Egiedat, some 15 km southeast of Mosul, after defeating the terrorist militants who fled their positions, the statement added.

Also in the day, the predominantly Shiite Hashd Shaabi units freed the villages al-Salam, Tal Mfeilka and al-Turkomaniya near the IS-held town of Tal Afar, some 70 km west of Mosul,

The presence of the Hashd Shaabi units near Tal Afar enabled them to cut off the IS supply routes from the west side of Mosul, and allowed both the paramilitary units and other Iraqi and Kurdish security forces to entirely isolate and surround the city Mosul.

On Tuesday morning, the paramilitary units began their advance to encircle the town of Tal Afar, preparing for the next stage to free it from the IS militants.

The units' presence in the whole area in west of Mosul would also enable them to secure the border areas between Iraq and neighboring Syria and would cut off the IS supply routes between Mosul and the Syrian city of Raqqa, the capital of IS self-declared caliphate.

On Friday, a report by the International Organization for Migration (IOM) said that after more than a month of military operations against IS militants in Mosul, some 72,990 civilians have fled their homes in the city and its adjacent districts and the number went up every day.

Iraqi Prime Minister Haider al-Abadi on Oct. 17 announced a major offensive to retake Mosul, the country's second largest city.

Since then, the Iraqi security forces have inched to the eastern fringes of Mosul and made progress on other routes around the city.

Mosul, some 400 km north of Iraqi capital of Baghdad, has been under the 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.