A few loud blasts and heavy gunfire was heard in Libya’s capital Tripoli in the early hours of Wednesday.
The cause of the firing was not immediately clear, but the Libyan capital has been on edge amid speculation that a UN-backed unity government, formed by the Tunis-based Presidential Council, was about to travel to Tripoli from Tunisia.
The Tripoli-based General National Congress (GNC) government and some armed factions in the city rejected UN-backed government and have warned it not to move.
GNC has declined to give permission last week for the United Nations envoy Martin Kobler to Libya to land in Tripoli.
GNC Prime Minister Khalifa Ghwell said in a statement late on Tuesday that the airspace had been closed to "protect the souls of the people following the Presidential Council's inappropriate behaviour."
Libya's chaos, five years after the uprising that led to the ouster and killing of longtime leader Muammar Gaddafi, has left the country deeply divided between two rival governments, and both rejects the unity government.
The unity government, brokered by the UN and headed by a little-known Libyan technocrat, Fayez Serraj, is supposed to replace the two rival administrations.
DAESH terrorists have exploited the years of chaos in Libya and taken control of a central Libyan city and its surroundings, which in turn has given new impetus to Western countries and the UN to try to piece the country back together.