Updated

Libya's state-run oil company says militants have attacked an oil field, killing eight guards before setting it ablaze.

National Oil Corporation spokesman Mohammed al-Harari tells The Associated Press that gunmen attacked al-Ghani oil field near the town of Zalla, some 750 kilometers (470 miles) southeast of the capital Tripoli. He says black smoke filled the sky above the facility.

It was not immediately clear if the militants seized control of the field or fled.

Militants believed to be affiliated with the Islamic State group have launched several attacks on oil facilities in recent weeks, forcing Libya to suspend some contracts. Militias have run amok in the country, which is now grappling with the worst unrest since the 2011 uprising that toppled and killed longtime dictator Moammar Gadhafi.