Ali al-Hassi said the Petroleum Facilities Guards were still in control of the neighbouring ports of Es Sider and Ras Lanuf, where at least nine guards were killed and more than 40 injured near the ports' perimeters on Monday and Tuesday.

Hassi said guards had recovered bodies of 30 Islamic State fighters, and had captured two military tanks and other vehicles from the militants.

He also said the guards had received air support from forces loyal to the General National Congress (GNC), the government that has controlled Tripoli since its rival, which was internationally recognised, moved to Bayda in the east in 2014.

Firefighters were trying to control four fires at Es Sider and one at Ras Lanuf. Two were triggered by Islamic State shelling, and three more had caught fire, Hassi said.