TRIPOLI // Islamist militiamen on Sunday stepped up their assault on Libya’s main airport, two days after the collapse of a truce with rival ex-rebels who control the facility, a security official said.

Local residents said the upsurge in violence killed at least one civilian when a rocket hit a house in the capital’s Qasr Ben Gheshir district near Tripoli international airport.

“The airport was attacked this morning with mortar rounds, rockets and tank fire,” airport security official Al Jilani Al Dahesh said.

“It was the most intense bombardment so far.”

Mr Al Dahesh said the militia which controls the airport, based in Zintan, south-west of the capital, and seen by Islamists as the armed wing of liberals within the government, responded with heavy fire.

Islamist militia first attacked the airport on July 13, forcing a halt to all flights.

The offensive has since caused extensive damage to planes and airport infrastructure that aviation officials say will keep it closed for months.

Pictures posted on social media showed a Libyan Airlines plane on fire as plumes of smoke billowed over the airport.

The carrier said on its Facebook page that one of its aircraft, a Bombardier CRJ900, was destroyed.

By midday on Sunday, fighting had spread to other sites on the airport road that are controlled by the Zintan militia.

Loud explosions were heard in the city centre, 25 kilometres away, as battles raged along the airport road.

The Islamists have been reinforced by militia allies from Misurata, a key battlefield in the 2011 uprising which toppled and deceased veteran dictator Muammar Qaddafi.

They have dubbed the operation to crush the Zintan militia “Libya’s Dawn”.

The rival sides are among several heavily-armed militias which hold sway in the oil-producing North African nation since the uprising.

Relentless violence across Libya in past months — including a war against Islamists in the east launched by a rogue general — has sparked fears of all-out civil war.

This has prompted foreign minister Mohammed Abdelaziz to plead for UN help to build up Libya’s army and police force and to protect vital sites, including the airport and oil installations.

The fighting mirrors a deadly power struggle between liberals and Islamists in the National General Congress, Libya’s parliament and top political authority.

A new parliament was elected last month after the GNC came under repeated accusations of trying to monopolise power.

Results of the vote had been due to be announced Sunday but the electoral commission announced a delay until Monday.

* Agence France-Presse