Forces loyal to Libya's UN-backed national unity government said on Monday they had seized the last areas of Sirte held by "Islamic State" (IS) militants, after more than six months of fighting.

"Our forces have total control of Sirte," official spokesman Reda Issa told news agencies AFP and Reuters.

The city, located on Libya's Mediterranean coast, had been held by IS militants since June 2015 and was the last major stronghold of the jihadist group in the north African country. It used to have some 120,000 residents, but loyalist forces said most had succeeded in fleeing after IS took over the city.

The fall of Sirte would be a significant setback for IS. The group has also been losing a great deal of ground in Syria and Iraq.

Fierce IS resistance

The offensive to retake the city, the home town of late former dictator Moammar Gadhafi, began on May 12. Initially, pro-government forces scored several rapid successes, but IS slowed their advance with suicide car bombings, snipers and improvised explosive devices.

The United States began giving aerial support to the local forces in August at the request of the Government of National Accord (GNA). At the time, US President Barack Obama said it was in America's national interest to defeat IS there.

Sirte is a major port city lying just 150 kilometers west of an oil-producing area and export terminals that are vital to Libya's economy. It is situated on the coast roughly halfway between the capital, Tripoli, in the west and second city Benghazi in the east.

The capture of Sirte by IS raised fears that the group might try to seize the nearby oil fields in a bid to fund its North Africa operations.

The city saw not only Gadhafi's birth in 1942, but also his capture and killing on October 20, 2011. Following his death, Libya fell largely into a state of lawlessness, with several groups fighting to take control of the country.

tj/se (AFP, Reuters, dpa)