Flights to and from Libya's international airports in Tripoli and Benghazi resumed late on Sunday after a strike by air traffic controllers, an airport source said.
"Traffic has resumed to Tripoli and Benghazi," the source said without elaborating.
The decision to strike was made at about 1000 GMT on Sunday without prior warning to airlines, aviation sources added earlier, forcing a Tunisair flight to remain grounded at Benina airport in the eastern city of Benghazi.
A Qatar Airways flight headed for Benghazi was redirected to Alexandria in Egypt.
Libyan air traffic controllers earlier gave different reasons for the strike, some saying it was over salary disputes, others that it was because of the security situation.
Air traffic at Benghazi reopened on Friday after a temporary suspension for what officials said were security reasons, three days after an attack on the US consulate in the city killed four Americans, including the ambassador.
A military source would say only that unspecified "threats" were behind the suspension.
An airport source said no official reason had been given for the closure of Benina from late Thursday to Friday, but speculated: "The threat of the possible presence of surface-to-air missiles could be behind the decision."
After the conflict that ousted dictator Moamer Kadhafi last year, Western nations involved in a NATO enforcement of a no-fly zone over Libya reported the disappearance of thousands of surface-to-air missiles capable of being fired from portable launchers.