A militia of Libyan ex-rebels entered Tripoli International airport with tanks and armoured vehicles and completely blocked air traffic on Monday, a day after their leader was arrested, officials said.

"It is total confusion. Everyone is fleeing. Several armoured vehicles and tanks are positioned on the tarmac, blocking traffic," an official at the airport told AFP.

"Cars mounted with anti-aircraft guns and armed men are surrounding the aircraft and preventing them from moving," another official said, adding that some passengers were forced to leave the planes.

The official Lana news agency, citing witnesses, confirmed the "assault," saying that the motive of the gunmen was to pressure the government to explain the detention of their leader, Abu Ajila al-Habshi.