Unidentified aircraft flew over Tripoli before dawn on Monday and loud explosions were heard, residents in the Libyan capital said, days after fresh clashes between militias prompted hundreds of people to flee.
Aircraft first flew over at around 2:00 am (0000 GMT) and a resident told AFP he heard a loud explosion which was followed by others.
"The explosions were clearly heard in eastern districts of Tripoli, 15 kilometres (10 miles) from the town centre," he said.
Television channel Libya Awalan (Libya First), close to dissident general Khalifa Haftar, said: "Military planes bombarded various positions" near Tripoli. It gave no further details.
Haftar has been conducting an operation against militant groups who have held sway in the eastern city of Benghazi since the fall of long-time dictator Moamer Kadhafi in 2011.
Official sources gave no details of the flights over Tripoli, where the international airport has been closed since July 13 amid battles between rival militias in the neighbourhood.
The airport, south of the city, is in the hands of nationalist fighters from Zintan in southern Libya, but they have been fending off a challenge from the Islamist-linked militia of Misrata, east of Tripoli, for control of a bridge giving access to the airport.
New skirmishes between the rival militias raged in Tripoli on Friday and Saturday, with grad missiles and artillery used but there were no immediate reports of casualties. State news agency Lana said around 1,000 families had fled the fighting.
The clashes quietened on Sunday when the Misrata brigade claimed to have taken a bridge and an army base, though the claim was impossible to confirm independently.
Libya's newly-elected parliament, meeting in the eastern city of Tobruk to avoid the Tripoli violence, called last Wednesday for foreign intervention to protect civilians.
Source: AFP