Jet fuel tanks at Tripoli's Mitiga airport were targeted in an attack on Saturday that caused a large fire, Libya's National Oil Corp (NOC) said.
Mitiga is the last functioning airport in the Libyan capital, though civilian flights stopped in March because of repeated shelling even before the country imposed a lockdown over the coronavirus pandemic.
The NOC statement, posted on the state-run company's Facebook page, gave no details of the attack but said firemen were working to bring the blaze under control.
Video shared with Reuters by an airport worker showed plumes of black smoke billowing over the apron.
The Libyan National Army (LNA) led by Commander Khalifa Haftar has been fighting for more than a year to capture Tripoli, seat of the internationally recognised Government of National Accord (GNA), with frequent shelling of the capital.
Pro-GNA forces have retaken some territory from the LNA during an escalation of fighting in recent weeks with the help of Turkish-supplied drones.