Air traffic controllers at Tripoli airport in Libya staged a strike over pay on Sunday that affected flights in the capital and other cities, the airport director said.
"They are striking over pay and for technical reasons," director Milad Maatouq said. "Negotiations are under way with the striking workers."
The strike hit airports in Tripoli and the eastern city of Benghazi, where certain flights take directions from air traffic controllers in the Libyan capital.
A Qatar Airways plane bound for Benghazi in the early afternoon was diverted to Alexandria in Egypt, a Reuters reporter said.
Several international airlines fly into Libya daily.
Libya's air traffic controllers have staged such strikes before. In December they walked off their jobs because they were unhappy about the appointment of new management.
Libya has been trying to return to business as usual after last year's war that toppled longtime leader Muammar Gaddafi. But security problems and chaos can still be disruptive.