The number of people killed in three days of protests in Libya has risen to 84, according to the New York-based group Human Rights Watch.
The group says 35 deaths were reported by one hospital alone in the second city, Benghazi, which is the main focus of unrest against Colonel Muammar Gaddafi's rule.
State media have warned of retaliation against critics of the Libyan leader, who has been in power since a coup in 1969.
Earlier Amnesty International said 46 people had been killed in a police crackdown on pro-democracy protestors in Benghazi.
Violent confrontations are reported to have spread to five cities so far, including reports of protests in the capital,Tripoli.
But Libyan state media said there had been pro-Gaddafi rallies in the capital.
Most protests are confined to the east around Benghazi, where support for Colonel Gaddafi has traditionally been weak, Reuters reports.
The demonstrations, sparked by uprisings in neighbouring Tunisia and Egypt, have produced unprecedented scenes in the oil exporting country, but little information has been emerging due to tight government control and media restrictions.
The BBC confirms that several websites - including Facebook and al-Jazeera Arabic - have been blocked.
Protests continue in Benghazi
Reports from Benghazi say thousands of protesters are continuing to clash with security forces and the city's airport has been closed.
In a statement on its website, Amnesty quotes sources at al-Jala hospital in Benghazi as saying 28 people died on Thursday, with the most common injuries being bullet wounds to the head, chest and neck.
Other reports suggest dozens more were killed on Friday, with a doctor at the hospital reporting that 35 bodies were brought in after an attempted protest outside the residential compound used by Colonel Gaddafi when he visits Benghazi.
Libyan officials have given no death toll, or commented directly on the unrest, but the authorities have issued a stark warning to protesters, saying they will meet a violent and thunderous response.
Amnesty says Libya has to rein in its security forces.
The BBC reports eyewitnesses as saying activists have set up camps in the eastern town of Al Bayda, where townspeople are burying 14 people killed in earlier clashes.