Libya's national assembly on Sunday approved a new interior minister after the incumbent submitted his resignation amid a rise in violence in the North African country.

Prime Minister Ali Zeidan last week nominated Tripoli police colonel Mohammed Khalifa al-Sheikh to take over from Ashour Shuail, after the latter said he would quit his post for "personal reasons", official sources said.

Shuail, former police chief in the eastern city of Benghazi, was named interior minister late last year to tackle Libya's biggest domestic policy challenge - establishing a legitimate, effective national police force.

However, armed violence persists in wide areas of the oil-producing state.

Ninety-nine out of 124 congress members present at the Sunday session voted to approve Sheikh as the new minister, the assembly's media office said.

"(Sheikh) is a professional policeman and had positive relations with the revolutionaries which is good," one congress member, who declined to be named, said after the vote.

"His CV looks good on paper and he explained his plan well."

Sheikh, from Tripoli's eastern Souq al-Jumaa neighbourhood, previously worked in various police stations in the capital and taught at a training academy before the 2011 war broke out.

He is said to have been in charge of the Tripoli operations room after the capital fell to rebels in August 2011. He later worked in the interior ministry and became an adviser to the leader of the national congress on security matters.

Libya is awash with weapons and armed attacks have increased in recent weeks, especially on police stations in Benghazi. Last month a car bomb devastated France's embassy in Tripoli, wounding two French guards.

Shuail has not publicly spoken about leaving, but his move came after congress passed a law banning anyone who held a senior post under Muammar Gaddafi from government, regardless of their part in toppling the dictator.

Shuail worked with the police authority under Gaddafi but defected in the early days of the 2011 uprising. In December he won an appeal clearing him of close ties to Gaddafi's regime.