A man who said he was armed with a grenade Friday hijacked a Libyan plane which landed on the Mediterranean island of Malta with 118 people on board, Malta's prime minister and government sources said.

The Airbus A320 had been on a domestic Libyan route operated by Afriqiyah Airways from Sabha in the south to the capital Tripoli but was re-routed.

"The Afriqiyah flight from Sabha to Tripoli has been diverted and has landed in Malta. Security services coordinating operations," Maltese Prime Minister Joseph Muscat said on his official Twitter account.

"It has been established that Afriqiyah flight has 111 passengers on board. 82 males, 28 females, 1 infant," Muscat said. There are also seven crew members.

The plane could be seen on the tarmac surrounded by military vehicles and all flights in and out of the airport have been either delayed or diverted to other destinations.

Maltese government sources told AFP that there was a single hijacker on board who had told the crew that he had a grenade and would release the passengers only if his as yet unspecified demands were met.

A source from Libya's unity government spoke of "hijackers" on board.

Malta International Airport tweeted: "MIA confirms there is an unlawful interference at the airport. Emergency teams dispatched".

Flights from Brussels, London and Paris had been due to land at the airport on Friday.

Libya has been in a state of chaos since the 2011 overthrow of Moamer Kadhafi left warring militias battling for control of different parts of the country.

Forces loyal to a fledgling national unity government recently took control of the coastal city of Sirte, which had been a bastion for the Islamic State group since June 2015.

Western powers have pinned their hopes of containing jihadism in the energy-rich North African state on the government but it has failed to establish its authority over all of the country.

A rival authority rules the country's far east, backed by the forces under military strongman Marshal Khalifa Haftar, who have been battling jihadists in second city Benghazi.

(AFP)