According to CNN, Libyan forces have retaken parts of Sirte from ISIS militants, gaining ground in the extremist group's most significant stronghold outside Syria and Iraq.

In the ongoing offensive, forces supporting the U.N.-brokered government gained control of a port late Friday after fierce clashes with ISIS militants and are in complete control of the al-Sarawa area east of Sirte, according to Al-Bunyan al-Marsous, a Libya monitor.

The offensive that has lasted almost two weeks has left dozens of fighters dead and around 400 others wounded, the Government of National Accord said, calling on the international community to provide urgent medical support to Libyan security forces.

The forces reopened a road between Sirte and a village around 70 kilometers (around 40 miles) east after sweeping for and removing improvised explosive devices, while the country's airforce carried out six air raids against the militants and their weaponry in Buhari, 3 kilometers to Sirte's south, according to Al-Bunyan al-Marsous.

The advance comes as ISIS loses more ground in Iraq and Syria, with forces supported by U.S.-led air strikes slowly moving closer in on its heartland Raqqa.

Sirte, a port city on the Mediterranean coast, was a popular tourist destination before it fell into the hands of ISIS. The extremist group has gained a foothold in the country in a power vacuum that hasn't been filled since collapse of Moammar Gadhafi's regime collapsed in 2011.

At first there were hopes that Libya would follow a more democratic path like its neighbor, Tunisia. But warring factions soon split over how to run the country, and civil war ensued. Two rival governments claimed to be the rightful leaders before signing a U.N.-backed peace deal in December.