Medics said on Sunday that five people were killed and 12 were wounded during clashes in eastern Libya between forces loyal to its internationally recognised government and militant groups.
On Saturday, residents said that fighting broke out in the town of Ajdabiya, near the oil port of Brega and a war plane attacked suspected militants’ positions in the town’s south.
Whether the militants were affiliated to ISIS or other groups is still unclear.
On Friday, ISIS killed five soldiers in an attack on a checkpoint manned by troops loyal to the Tobruk-based internationally recognised government outside the town of Ajdabiya, 270 km (167 miles) from the city of Tobruk.
The government sent reinforcements to the town, but two soldiers were killed, while another 15 have been missing since.
After the toppling of former autocratic ruler Muammar Gaddafi, a security vacuum has grown in Libya, with the country controlled by two rival administrations - each with its own government and parliament - who are fighting for control.
After Gaddafi's ouster, the country’s various factions became split along political, regional and tribal lines.
ISIS, which seized swathes of Syria and Iraq, has taken control of the central city of Sirte, west of the town of Ajdabiya, and has been responsible for numerous attacks in the country.