Cornered IS militants try to swim out of Sirte

Forces supporting the UN-backed Government of National Accord [GNA] "thwarted the escape of two members of the terrorist [IS] via the sea", they said.

"The two [IS] members of Tunisian origin slipped out at dawn towards the sea and tried to escape by swimming," the LANA news agency reported a military source within the forces as saying.

On Saturday, the GNA forces stopped "six Daesh members who tried to flee at dawn by swimming in the sea", they said in a statement on their operation's official Facebook page.

The GNA forces are pressing an almost seven-month-old offensive to oust IS from the Mediterranean city, some 450 kilometres [280 miles] east of the capital Tripoli.

They began the operation to retake Sirte in May and quickly seized large areas of the city.

But stiff resistance from IS fighters cornered in their last holdouts by the sea have slowed the advance of government troops. 

For several weeks, loyalists have been inching their way to the last remnants of IS territory house by house.

The militants are involved in fierce fighting in the seaside district of Giza al-Bahriya, but have failed to dislodge the last pockets of IS fighters.

GNA fighters have attempted to secure safe passage for civilians out of the neighbourhood, their Facebook page said.

Almost seven months of fighting have left nearly 700 GNA fighters dead and 3,000 wounded. The IS death toll is not known.

Libya descended into chaos after the 2011 uprising that toppled and killed longtime dictator Muammar Gaddafi, and IS overran Sirte in June 2015.