The top commander of the Libyan army's special forces said on Monday his troops had joined forces with renegade general Khalifa Haftar, who has said he wants to purge the North African country of militant Islamists.

"We are with Haftar," Wanis Bukhamada told Reuters in the eastern city of Benghazi. On live television he had earlier announced his forces would join "Operation Dignity", as Haftar calls his campaign.

The special forces are the best trained troops of Libya's nascent army. They have been deployed since last year in Benghazi to help stem a wave of car bombs and assassinations, but struggled to curb the activities of heavily-armed Islamist militias roaming around the city.

Earlier, a Libyan air force base in the eastern city of Tobruk also said it was allying itself Haftar. "The Torbuk air force base will join...the army under the command of General Khalifa Qassim Haftar," the statement said. Staff at the air base confirmed its authenticity.

It had been unclear how many troops supported Haftar, whose forces launched an attack on Islamist militants in Benghazi on Friday in which more than 70 people died.

Heavily-armed gunmen apparently loyal to Haftar had stormed parliament on Sunday demanding it be suspended and power handed over to a 60-member body that is rewriting Libya's constitution.

The Tobruk air base development was significant as it was not clear how much backing Haftar's men had within Libya's nascent regular armed forces and the powerful brigades of former rebels who had toppled Muammar Gaddafi in 2011.

Any alliance of militias lining up against Islamist groups threatens to deepen chaos in the OPEC oil producer, whose fragile government is struggling to gain legitimacy and impose its authority.

Haftar, once a Gaddafi ally who turned against him over a 1980s war in Chad, fueled rumors of a coup in February when he appeared on television in uniform calling for a caretaker government to end the crisis in Libya.

His forces attacked militants in the eastern city of Benghazi on Friday. More than 70 people were killed.

Uncertainty over prime minister

Since the end of Gaddafi's one-man rule, the main rival militias of ex-rebels have become powerbrokers in Libya's political vacuum, carving out fiefdoms.

Compounding the anarchy, Libya's outgoing government demanded parliament to go into recess after the forthcoming vote on the 2014 budget until the next election later this year, according to a statement issued after a cabinet meeting.

Haftar and other militias have demanded that a parliament, paralyzed by infighting step down.

The government demanded that parliament repeat a vote on a new prime minister. Business Ahmed Maiteeq was named as new premier two weeks ago in a chaotic vote disputed by many lawmakers.

"This government submits a national initiative to the General National Congress (GNC) to reach a national consensus during this decisive phase," the statement of the cabinet of outgoing premier Abdullah al-Thinni said.

Should the GNC fail to agree on a new premier then Thinni's cabinet should stay, it said. There was no immediate reaction from the GNC which is unlikely to give up power without a fight.

Benghazi airport remains closed

Tripoli was quiet on Monday with most people staying indoors after fighting raged across the capital on Sunday. Two people were killed in that violence.

The international airport was open though some flights were cancelled as travelers could not easily reach it. But authorities extended the closure of Benghazi airport for another week because of the unrest, the airport director said. It was attacked with rockets overnight.

Saudi Arabia closed its embassy in Tripoli and evacuated its diplomatic staff due to security reasons on Monday.