Tripoli air traffic was suspended overnight for "security reasons", the Libyan capital's only operating airport said Sunday after clashes intensified for control of the city.
At least two flights were re-routed from Mitiga airport to Misrata, more than 200 kilometres (125 miles) to the east, the airport's authorities said on their Facebook page.
They said flights had resumed early in the morning to Mitiga, east of the capital.
The former military airbase was hit by an air strike on April 8 and has since only operated between 5:00 pm and 8:00 am (1500 and 0600 GMT).
The raid was claimed by commander Khalifa Haftar's Libyan National Army, which days previously had launched an offensive to take the capital.
Clashes intensified on Saturday when forces loyal to the Tripoli-based Government of National Accord announced a counter-attack against Haftar's fighters.
Explosions were heard from the city centre overnight, and some witnesses said there were air strikes.
At least 227 people have been killed since Haftar's forces launched their offensive, the World Health Organization said Sunday, adding that a further 1,128 have been wounded.
As well as air raids, fighters have been engaged in clashes on the ground. The warring sides have traded accusations of targeting civilians.
Haftar's offensive is the latest round of fighting in a years-long struggle for control of Libya following the NATO-backed rebellion that toppled and killed longtime dictator Moamer Kadhafi.
The latest escalation comes years after Tripoli's only international airport was severely damaged during fighting.
Since then Mitiga airport has been used for civilian air traffic, with Libyan airlines operating internal flights and international ones to countries including Turkey.