Rockets were fired at the only working airport in the Libyan capital Tripoli overnight, with no immediate reports of casualties or damage, an airport source said early Wednesday.
It came within days of Mitiga International Airport's reopening after it was forced to close for a week because of deadly clashes between rival militias in and around Tripoli.
A Libyan Airlines flight was diverted to Misrata airport, some 200 kilometres (120 miles) east of the capital, the source said, adding that preparations were underway to move planes on the tarmac in Tripoli to Misrata as well.
The airport had reopened on Friday after a ceasefire overseen by the UN was signed between the armed groups.
The agreement has largely been respected but witnesses reported brief clashes in the south of the capital on Tuesday night.
In August, at least three rockets landed in the airport's vicinity, forcing staff to reroute flights to Misrata.
The bloody conflict mostly in Tripoli's southern suburbs has killed at least 50 people and wounded 138 others, most of them civilians, since August 27, according to the health ministry.
More than 1,800 families have fled the fighting to nearby towns or have had to seek shelter in other districts of Tripoli, authorities have said.
A former military airport, Mitiga was first opened to civil air traffic after the destruction of Tripoli's international airport in the south of the city during clashes in 2014.
Since then only Libyan airlines have operated in the country, running internal flights and regular connections to a handful of countries, including Tunisia and Turkey.
Libyan airlines are banned from European Union airspace for "security reasons".