Benghazi : Libyan troops have opened fire with machine-guns and large-calibre weapons on anti-government protesters, witnesses say.
An unknown number of people, including children, are said to have been killed.
Witnesses described scenes of chaos as snipers shot from the roofs of buildings
'Dozens killed' on SaturdayBut there have been no reports of major protests in the capital Tripoli.
The Libyan leader, Colonel Muammar Gaddafi, is the Arab world's longest-serving leader, having ruled the oil-rich state since a coup in 1969.
Libya is one of several Arab countries to have experienced pro-democracy demonstrations since the fall of long-time Tunisian President Zine El Abidine Ben Ali in January. Egypt's Hosni Mubarak was forced from power on 11 February.
Benghazi, about 1,000 km (600 miles) from Tripoli, has been the main focus of the demonstrations against Col Gaddafi's 42-year rule.
Troops opened fire on people attending a funeral there on Saturday, killing 15, both the Associated Press news agency and al-Jazeera television said.
But an eyewitness told Reuters news agency that many more had actually died.
A Benghazi resident told the BBC that security forces inside a government compound had fired on protesters with mortars and 14.5mm machine guns - a heavy machine gun typically produced in the former USSR.
They were, he said, machine-gunning cars and people indiscriminately. "A lot [of people] have fallen down today," he added.
Other witnesses spoke of snipers firing at protesters from rooftops and there were widespread reports of foreign mercenaries from sub-Saharan Africa being brought in to attack protesters.
A doctor told the BBC that situation in the city was "like hell", saying he had been seeing people with gunshot wounds being carried into his hospital all day.
'Liberated' cityAnother witness who spoke to Reuters said that the government compound was the only part of Benghazi still under military control.
"The rest of the city is liberated," he said.
He said that local government offices and police stations in the city had been burnt down and thousands of protesters were organising around the courthouse, equipped with makeshift clinics, ambulances, speakers and electricity.
His account could not be verified independently, and Libyan state media have ignored the unrest, focusing instead on pro-Gaddafi rallies in Tripoli.
Human Rights Watch put the death toll since Wednesday, when protests erupted, at 84, not counting those killed on Saturday.
Similar casualty figures have been reported by foreign broadcasters for the same period while.
