Security forces have killed 24 people in the past two days of unrest in Libya, Human Rights Watch has said.
Soldiers sought to put down unrest in Libya's second city today and opposition forces said they were fighting troops for control of a nearby town.
Protests in Libya are inspired by the revolts that brought down long-serving rulers of neighbouring Egypt and Tunisia.
The demonstrations have led to violence unprecedented in Muammar Gaddafi's 41 years as leader of the oil exporting country.
The capital Tripoli has been calmer, with Gaddafi supporters staging demonstrations of their own.
The leader appeared briefly in the early hours of this morning at Green Square in the centre of Tripoli, surrounded by crowds of supporters. He did not speak.
A sermon at Friday prayers in Tripoli, broadcast on state television, urged people to ignore reports in foreign media 'which doesn't want our country to be peaceful, which ... is the aim of Zionism and imperialism, to divide our country.'
Gaddafi's opponents, using Facebook and Twitter, had called for new protests after Friday prayers, when most Libyan men visit the mosque.
A Benghazi resident told Reuters by telephone the city appeared to be calm after prayers but said local people were unsure what would happen following funerals of people killed in the protests.
Opponents of Gaddafi had designated yesterday as a day of rage to try to emulate uprisings sweeping through North Africa and the Middle East.
Unrest continued well into the night.
The demonstrations have been focused in the country's east, including its second largest city, Benghazi, where support for Gaddafi has been historically weaker than in the rest of the country.
The area is largely cut-off from international media.
‘Last night was very hard, there were a lot of people in the street, thousands of people. I saw soldiers in the street,’ a resident who lives on Benghazi's main thoroughfare, Nasser Street, told Reuters.
New York-based rights group Human Rights Watch said that according to its sources inside Libya, security forces had killed at least 24 people over the past two days.
Exile groups have given much higher tolls, which could not be confirmed.
The privately-owned Quryna newspaper, based in Benghazi, said security forces overnight fired live bullets at protestors, killing 14 of them.
It published photographs of several people lying on hospital stretchers with bloodstained bandages.
Two Swiss-based exile groups said anti-government forces, joined by defecting police, were battling with security forces for control of the town of Al Bayda, 200km northeast of Benghazi - a scene of deadly clashes this week.