The UN Security Council has passed a resolution calling for an immediate ceasefire in Libya and sanctions against those involved in the surge in violence there between rival militias.
Libya’s ambassador to the UN called the resolution a “milestone”, but has warned of “a full-blown civil war”.
The list of those to face sanctions is yet to be decided.
The Security Council has been alarmed by the increase in fighting between militia groups and army factions.
Recent clashes have centred on the international airport in the capital, Tripoli, which is now under the control of militias from Misrata and other cities operating under the banner Libya Dawn, including some Islamist groups.
They took it from the hands of a Zintan-based militia, despite alleged air strikes carried out by Egypt and the UAE targeting the Islamist-linked group.
Libya is also facing political turmoil, with two rival leaders and assemblies currently operating in two different parts of the country, each backed by rival armed groups.
Arms embargo tightened
On Wednesday, the UN Security Council unanimously approved a resolution that threatened to impose sanctions, such as asset freezes and travel bans, against the leaders of warring militias and those supporting them.
It said that sanctions would target individuals and groups that endanger the security of Libya or undermine the political transition.
It also tightens an arms embargo already in place by requiring advance approval of any sale or transfer of arms to the country.
Analysis: Rana Jawad, BBC News, Tripoli
It isn’t clear yet who exactly will be targeted by sanctions but the implications are that senior commanders of militias on all sides that have taken part in the violence may soon find themselves facing travel bans and an asset freeze.
More importantly perhaps, the resolution also brings into focus external players involved in backing competing militias in Libya. Social media reaction has been swift, with many wondering whether militias would even hear of or care about a resolution adopted by the UN Security Council.
The British ambassador to Libya, Michael Aaron, answered one of these questions on twitter, saying: “No one wants to be identified by the UN as responsible for these acts of violence – it will have an effect.”
That may be true, particularly in the Libyan context where the recent warring militias and their political backers are keen on proving themselves as the ones that the international community should be dealing with as the “legitimate representatives” in the country – militarily and politically.
The West has made it clear they are only backing elected institutions.
The question now is how long will it take before all parties realise that the time has come for some real negotiations.
Libya’s ambassador to the UN, Ibrahim Dabbashi, warned the council on Wednesday that the situation in Libya had “become even more complicated and the situation might unravel into a full-blown civil war if we’re not very careful and wise in our actions”.
Libya’s government has failed to bring under control many of the militia groups which overthrew Muammar Gaddafi in the 2011 uprising.
Mr Dabbashi said it was crucial that these groups were disarmed.
The government’s limited capacity to counter the spread of terrorist groups may have created a fertile ground for “a mounting danger in Libya and beyond,” he added.
The outgoing UN special envoy to Libya, Tarek Mitri, said the situation in Libya was of “grave concern”.
“The threat from the spread of terrorist groups has become real. Their presence and activity in a number of Libyan cities are known to all,” he said in his final address.
The latest developments come two days after several members of Libya’s previous Islamist-dominated parliament reconvened and voted to disband the country’s interim government.
Backed by the Misrata-led brigade, the General National Congress (GNC) refuses to acknowledge its successor assembly, the House of Representatives, which was elected in June and is dominated by liberals and federalists.
The house, which is based in Tobruk and is recognised by the international community, has dubbed the groups in control of Tripoli “terrorist organisations”.
Libyan lawmakers within the House of Representatives voted earlier this month in favour of asking the UN to intervene in the ongoing militia battles around the country.
Hundreds of people have died since fighting erupted in Tripoli in July.