Gunfights broke out in the Libyan capital Tripoli between dozens of supporters of deposed leader Muammar Gaddafi and forces of the new government.
It was the first sign of armed resistance to the National Transitional Council (NTC) in the city since its rebel brigades seized the capital in August.
Hundreds of NTC fighters in pick-up trucks careered towards the Abu Salim neighbourhood, a centre of support for Gaddafi and the two sides exchanged automatic and heavy machinegun fire.
Local people said that a group of up to 50 armed men had appeared in Abu Salim earlier in the day and had chanted pro-Gaddafi slogans. NTC men said fighting also broke out in three other nearby neighbourhoods.
Though the battles were small and casualties seemed light, it raised concerns the interim government could face an insurgency by Gaddafi loyalists.
The former leader has released a number of audio recordings calling on loyalists to fight back.
Gaddafi supporters are still holding out in two towns; Sirte, on the coast in the centre of the country, where a small pocket is battling on after weeks of fighting, and Bani Walid, a small town inland from Tripoli.
Government forces pushed tanks deep into Sirte on Friday to try to smash the last pocket of resistance by Gaddafi loyalists in his home town.