Security forces in Libya's second city have fired to disperse a crowd of mourners.
A large crowd got into a confrontation with security men after a funeral procession to bury people killed in the worst unrest of Muammar Gaddafi's four decades in power.
Human Rights Watch said 35 people were killed in the city late on Friday, in the worst night of violence since protests started this week to try to emulate uprisings in neighbouring Egypt and Tunisia.
The New York-based watchdog said its tally for the number of dead was now 84 after three days of violence centred on the restive region around Benghazi, 1,000 km (600 miles) east of the capital Tripoli.
Benghazi cleric Abellah al-Warfali said he had a list of 16 people being buried on Saturday, most with bullet wounds to the head and chest.
"I saw with my own eyes a tank crushing two people in a car," he said. "They hadn't done any harm to anyone."
The Libyan government has not released any casualty figures or made any official comment on the violence.
In London, British Foreign Secretary William Hague said he had reports that heavy weapons fire and sniper units were being used against demonstrators. "This is clearly unacceptable and horrifying," he said in a statement.
Away from the eastern region, Libya appeared calm.
In Green Square in the centre of Tripoli, next to the walled old city, several hundred people gathered waving portraits of Gaddafi and chanting "Our revolutionary leader!" and "We follow your path", a Reuters reporter said.
Libya-watchers say an Egypt-style nationwide revolt is unlikely because Gaddafi has oil cash to smooth over social problems, and is still respected in much of the country.
