MOSUL, Iraq, Feb. 27 (Xinhua) -- Iraqi forces on Monday continued fierce clashes against Islamic State (IS) militants in western Mosul and seized a neighborhood in the southern outskirts of the embattled city, the Iraq military said.

Federal police and interior ministry special forces, known as Rapid Response, recaptured al-Tayaran neighborhood and then raised the Iraqi flag over some of its buildings, Lt. Gen. Abdul-Amir Yarallah, from the Joint Operations Command (JOC), said in a press release.

The troops are clearing the neighborhood from IS militants, who sustained heavy casualties after days of fierce fighting, Yarallah said without giving further details.

Federal police and rapid response forces are also fighting in the adjacent neighborhood of Jawsaq and are focusing on securing a strategic bridge, known as 4th Bridge, across the Tigris River, a security source told Xinhua on condition of anonymity.

On Sunday, Yarallah said that Counter-Terrorism Service (CTS) forces completely liberated al-Mamoun neighborhood after three days of battles against IS militants in southern Mosul, which is locally known as the left bank of Tigris River.

CTS special forces also entered in the adjacent neighborhood of Wadi Hajar and are fighting fierce clashes with the IS militants inside the neighborhood, according to the security source.

Iraqi Prime Minister Haider al-Abadi, who is also the commander-in-chief of the armed forces, announced on Feb. 19 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 eastern Mosul, or the left bank of Tigris, after more than 100 days of fighting against IS militants.

However, the western part 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 government forces abandoned their weapons and fled, enabling IS militants to take control of parts of Iraq's northern and western regions.