At least seven people were killed and dozens wounded in clashes on Saturday between protesters and a Libyan militia operating with Defence Ministry approval in the eastern city of Benghazi, a doctor in the city said.
Residents said dozens of protesters had demonstrated outside the headquarters of the Libya Shield brigade demanding the disbanding of militias who have yet to lay down their weapons nearly two years after the overthrow of longtime dictator Muammar Gaddafi.
A doctor at a Benghazi hospital said he had counted seven dead from the clashes and "dozens" of wounded.
Resentment against the militias, some of which have been co-opted or licensed by a central government whose own forces are too weak to maintain security, has been growing in recent months, especially after militiamen laid siege to ministries in Tripoli last month to force their will on the National Assembly.
The Libya Shield brigade is made up of former rebel fighters who say they are aligned with the Defence Ministry.
"A group of protesters started protesting against the presence of militias. They were calling for the disbanding of groups to rebuild the army," said a Benghazi resident who declined to be named.
"As I was leaving, I saw protesters throwing stones and the other side fired back."
A spokesman for the security operations room in Benghazi said: "Initial reports say 18 people were injured and two were killed. No military action has been taken as of yet. We are waiting for elders to intervene."
A Reuters reporter at the scene heard shooting and counted at least a dozen wounded people being carried to nearby ambulances.
Ahmed Belashahr, a local activist, said: "People protested because they believe militias go against Libya's stability, which can only be achieved through a proper army and police."
Members of the Libya Shield brigade were not immediately reachable for comment.
Libya's new rulers are still struggling to impose their authority on a myriad of armed groups who often take the law into their own hands.
Last September, shortly after an attack on the U.S. mission in Benghazi in which the U.S. ambassador and three other Americans were killed, the city saw a huge outpouring of public anger at the militias.
The government has taken a two-track approach - shutting down militias that operated without official government permission, but also offering public backing to many of the most powerful armed groups, which have official licences to operate.