"The groups acting under the names of Fajr Libya (Lbyan Dawn) and Ansar al-Sharia are terrorist groups and outlaws that are rising up against the legitimate powers," parliament said in a statement issued last night.
The parliament, which sits in Tobruk, 1,600 kilometres (1,000 miles) east of the capital, said it was determined to deal with the challenge through the regular armed forces.
Fajr Libya is a coalition of Islamist militias, mainly from Misrata, east of the capital, while Ansar al-Sharia, which Washington also brands a terrorist group, controls around 80 per cent of the eastern city of Benghazi.
Fajr Libya yesterday said it had captured Tripoli's battered international airport from nationalist militiamen.
Also Read
The announcement came a day after an unidentified warplane raided Islamist positions around the airport, killing 13 fighters, a Fajr Libya spokesman said.
The fall of the airport would be a major defeat for the nationalist fighters from Zintan, southwest of Tripoli, who have held it since the overthrow of long-time dictator Moamer Kadhafi in 2011.
Al-Assima, in a news bulletin, said equipment was destroyed and the crew went missing.
On the political front, the outgoing provisional General National Congress (GNC), which was dominated by Islamists, was to resume operations at the request of Fajr Libya, despite being superseded by parliament, its spokesman said.
The airport 30 kilometres (20 miles) south of the Libyan capital, has been shut since July 13 because of the deadly clashes between the Islamists and the Zintan force.
The Islamist fighters charged that Libya's provisional government and parliament were "accomplices" to the raid and had lost their legitimacy.
Today, Egypt, whose leadership is fiercely anti-Islamist, denied any role in the air raid.