Libyan officials say Islamic State militants have attacked one of the country's major oil terminals, setting storage tanks on fire at the coastal Ras Lanuf facility.

State-run National Oil Corporation's spokesman, Mohammed al-Hariri, and Osama al-Hadairi, the spokesman for the oil facilities' security unit, say the attack took place early Wednesday.

There were no details on the size of destruction or possible casualties.

The IS affiliate in Libya, which controls the central city of Sirte, has carried out several such attacks and destroyed at least a dozen oil tanks. Attacks on the nearby Sidra oil port completely destroyed 16 out of 19 fuel tanks there, dealing a heavy blow to Libya's already embattled oil sector.

Libya slid into chaos following the 2011 ouster and killing of longtime dictator Muammar Gaddafi.