Renewed protests turned violent across Libya, with opposition activists saying dozens were shot dead during funerals and marches for those killed in anti-government demonstrations earlier this week.
The protests against the rule of Libyan leader Muammer Gaddafi had spread to the capital Tripoli by Friday night. Witnesses reported people taking to the streets in a number of western neighbourhoods.
Sources from northeastern city of Benghazi told DPA that 25 protesters were killed there on Friday. There was no independent or official confirmation.
Residents of Benghazi also reported that police there had been replaced with military troops.
Two more protesters were shot dead in the northern city of Qubah, the opposition National Front for the Salvation of Libya (NFSL) said on Friday.
Emboldened by revolutions in Tunisia and Egypt, thousands of Libyans are calling for the ouster of Gaddafi, who has been in power for 41 years.
"We do not want Gaddafi's compromises and his son's bribes. We want them out. We are demonstrating peacefully," one Libyan activist wrote on the social-networking site Twitter, which has emerged as one of the rallying tools of all the Middle East protests.
The opposition group NFSL said the al-Jdaida prison in Tajoora, also on the north coast, was burnt and prisoners had been released. It was not immediately clear how the fire broke out.
There were also unconfirmed reports that prisoners in a jail in Benghazi and in other northern cities had escaped, according to Libyan websites.
While most of the clashes and unrest took place in the northeast of the country, Libyan sources said the western part of the country was quiet.
Opposition groups claimed that by Thursday night, 45 people were killed, while the New York-based activist group Human Rights Watch estimated that 24 people had died in clashes with security forces.
The Quryna newspaper, which has close ties to Gaddafi's son, Saif al-Islam, reported that 14 people were killed in Benghazi Thursday, after police used live ammunition against protesters during several days of protests.
Meanwhile, the Libyan opposition accused authorities of providing more arms to the elite army brigade Khamees Gaddafi, named after one of the sons of the Libyan leader.
The opposition website Libya Al-Youm said that the brigade had attacked protesters in the north, a move it alleged had left up to 30 people dead.
Earlier reports had said that mercenaries from other African countries, including Chad, were also being recruited to attack protesters.
Libya Al-Youm said that helicopters landed briefly to provide the brigade with weapons in the coastal cities of Bayda and Shahhat. Three of its soldiers were killed in the clashes, according to the online report.
Human Rights Watch also accused Libyan authorities of arming people to attack protesters and sending out text messages that call upon "nationalist youths" to go out and "defend national symbols".
"Using security forces and armed thugs to deny people the right to express their opposition to the government increasingly looks destined to fail," the group noted.
State television, meanwhile, broadcast a Muslim preacher warning people against chaos and blaming ongoing pro-democracy protests in the country on Israeli interference.
"Adhere to the security of your country," the preacher said in the Friday sermon, warning Libyans to "beware of Zionist conspiracy theories" against their country.
For his part, Gaddafi attended a pro-government rally in the capital Tripoli, state television reported.
One of his sons, al-Saadi - who has played football for several Italian clubs - is now to be sent to Benghazi to help implement an "unprecedented development plan", the Al-Watan newspaper reported on Friday.