TRIPOLI: Libya's government said on Tuesday it was considering calling for international forces to help re-establish security after deadly clashes closed Tripoli airport, severing air links with the outside world.
On Monday, the United Nations announced it was evacuating its remaining staff from Libya because of the deteriorating security situation.
With liberal and Islamist militias locked in a brutal power struggle, the country's main international airport came under renewed attack late on Monday, for the second straight day.
Dozens of rockets -- including one that hit a plane -- were fired, killing a security guard and wounding six others, officials said.
The airport had already been shut down for at least three days after the Zintan militia which controls it was attacked by Islamist fighters on Sunday.
Al-Jilani al-Dahech, a security official at Tripoli airport, told AFP that the control tower was hit, along with an aircraft belonging to private Libyan carrier Buraq Airlines.
Shortly after the latest attack the government said it was "looking into the possibility of making an appeal for international forces on the ground to re-establish security and help the government impose its authority".
The statement from a spokesman added that the forces would help protect civilians, prevent anarchy and allow the government to build up the army and police.
NATO warplanes helped to overthrow dictator Moamer Kadhafi in 2011, sparking a power struggle between rival armed groups that has wracked the oil-rich state.
Growing international concern
Fighting between militias has intensified since a general election in June, and the UN said it was withdrawing its remaining staff.
"UNSMIL (United Nations Support Mission in Libya) temporarily withdrawing staff from Libya because of security situation," the mission, which had already pulled out dozens of personnel last week, said in a statement.
"After the latest fighting on Sunday and because of the closure of Tripoli international airport, the mission concluded that it would not be possible to continue its work... while at the same time ensuring the security and safety of its staff," it said.
UN staff would return as soon as security conditions permitted, the statement added.
Witnesses said a UN convoy left Tripoli on Sunday by road headed for the Tunisian border, 170 kilometres to the west.
The growing lawlessness plaguing Libya has heightened international fears of the conflict becoming more widespread.
Speaking in Vienna on Tuesday, US Secretary of State John Kerry said Washington was "deeply concerned" about the levels of unrest in Libya, and was "working very hard to find political cohesion".
"Every single day in the State Department we make assessments about the level of violence, about our personnel who are there, about our embassy."
Libya's neighbours -- Algeria, Chad, Egypt, Niger, Sudan and Tunisia -- issued a call for dialogue on Monday.
They agreed at talks near Tunis to set up twin commissions to broker talks and attempt to prevent any spillover of violence.
Also on Monday, Libya suspended all flights to and from third city Misrata, east of the capital, which is dependent on Tripoli airport for its operations.
"Libya is now practically cut off from the outside world," an airport source said.
There are now only two other airports operating, at Bayda and Tobruk in the east, the source said.
Islamist vs liberals
Sunday's Tripoli airport attack was claimed by Islamist militias determined to oust the Zintan group from key sites it controls south of the capital, including the airport.
At least 10 aircraft of Libya's main carriers Afriqiyah Airways and Libyan Airlines were damaged in the fighting, a security official said.
The attack was beaten off, but there were also clashes at other Zintan-controlled sites for several hours, notably on the road to the airport.
Libya has been awash with weapons since the uprising three years ago that toppled and killed Kadhafi.
Successive interim governments have struggled to establish a strong army and police force, giving former rebel groups a free hand to act.
The disciplined Zintan militia has sided with well-armed forces loyal to renegade former general Khalifa Haftar who launched an offensive against Islamist militias in second city Benghazi in mid-May.
Eastern Libya, particularly its main city Benghazi and the hill town of Derna, have become jihadist strongholds.
Renewed clashes broke out on Monday between troops and Islamist militia vying for control of Benghazi's Al-Jala hospital, which has been held for weeks by extremists.
A hospital source said three people were killed and 30 wounded in the violence. (AFP)