Fighters on Thursday attacked two oil terminals at Ras Lanuf and Al-Sidra held by Haftar's group, inflicting fresh disruption on an industry that forms the chaos-hit country's economic backbone.

A spokesman for Haftar's self-styled Libyan National Army, which controls most of the country's east, said its aircraft on Friday bombarded reinforcements headed to join the "terrorist groups".

The head of Libya's National Oil Company (NOC) blamed Ibrahim al-Jadhran, leader of a group opposed to Haftar that for years blocked the oil facilities, for the attack and said his forces had seized both sites.

Jadhran has kept a low profile since 2016, but appeared in a video on social media on Thursday, saying he had formed a coalition to take over the oil sites.

The NOC said Thursday it had evacuated staff "due to armed clashes in the area", with production falling around 240,000 barrels per day.

Rival political authorities and militias have been vying for control of territory and Libya's oil wealth since the 2011 uprising that ousted and killed dictator Moamer Kadhafi.

The two terminals in eastern Libya had already been severely damaged in clashes between the two groups in 2016 and 2017.

The attack on the oil facilities comes after feuding Libyan leaders, including Haftar, agreed to try to hold elections this December in line with UN plans to stabilise the country.

Haftar supports a rival administration in the east opposed to the weak internationally-backed government in Tripoli.