Libyan ex-rebel fighters protesting against a new government line-up lifted their siege on the national assembly building on Friday after occupying it for more than 24 hours, an AFP journalist reported.

Traffic was flowing freely again on the road leading to the assembly and the adjacent Rixos hotel, with police cars deployed at the entrances and at nearby junctions.

"They left this morning, peacefully and without problems," a policeman stationed at one of the outer gates of the compound told AFP.

Dozens of armed men had surrounded the assembly building on Thursday, blocking off traffic with vehicles mounted with heavy weapons as a protest over the new cabinet approved by the assembly on Wednesday escalated.

Many protesters were former rebels who fought in the uprising that toppled veteran dictator Moamer Kadhafi last year.

Some of the vehicles mounted with weapons remained inside the assembly compound overnight but were partly hidden from view by banners put up by the protesters.

"The revolutionaries demand a government of free men," read one. "You were elected to serve the people, not to disappoint them," read another.

Ex-rebels had completely withdrawn by the evening, an AFP photographer said.

An assembly official said that the protesters had agreed to disperse after premier-designate Ali Zeidan received a delegation to hear their grievances concerning his cabinet choices.

"They met with prime minister Ali Zeidan yesterday (Thursday) and asked him to change some ministers," he said.

The show of strength by the former rebels, some now in units at least nominally under government command, highlights the volatile security situation in a country still awash with weapons more than a year after Kadhafi's death, and still lacking a strong army or police force.

Despite the national assembly approving Zeidan's 30-member cabinet on Wednesday, assembly members can still raise objections to individual nominees, some of whom have been criticised for past links to Kadhafi's toppled regime.

Assembly president Mohammed Megaryef has denounced the "psychological pressure" placed on elected representatives after protesters barged into the chamber and derailed a first attempt at a vote on the new cabinet on Tuesday.