(New York) - Government security forces have killed at least 84 people in three days of protests in several cities in Libya, Human Rights Watch said today, based on telephone interviews with local hospital staff and witnesses.

The Libyan authorities should immediately end attacks on peaceful protesters and protect them from assault by pro-government armed groups, Human Rights Watch said.

Thousands of demonstrators gathered in the eastern Libyan cities of Benghazi, Baida, Ajdabiya, Zawiya, and Derna on February 18, 2011, following violent attacks against peaceful protests the day before that killed 20 people in Benghazi, 23 in Baida, three in Ajdabiya, and three in Derna. Hospital sources told Human Rights Watch that security forces killed 35 people in Benghazi on February 18, almost all with live ammunition.

"Muammar Gaddafi's security forces are firing on Libyan citizens and killing scores simply because they're demanding change and accountability," said Joe Stork, deputy Middle East and North Africa director at Human Rights Watch. "Libyan authorities should allow peaceful protesters to have their say."

Muammar Gaddafi has ruled Libya for 41 years.

The protests in Benghazi on February 18 began during funerals for the 20 demonstrators killed by security forces the day before. Eyewitnesses told Human Rights Watch that security forces with distinctive yellow uniforms opened fire on protesters near the Fadil Bu Omar Katiba, a security force base in the center of Benghazi. One protester told Human Rights Watch he witnessed four men shot dead.

By 11 p.m. on February 18, Al Jalaa Hospital in Benghazi had received the bodies of 35 people killed that day, a senior hospital official told Human Rights Watch. He said the deaths had been caused by gunshot wounds to the chest, neck, and head. Two sources at the hospital confirmed to Human Rights Watch that the death toll for February 17 was 20, and that at least 45 people had been wounded by bullets.

The senior hospital official told Human Rights Watch, "We put out a call to all the doctors in Benghazi to come to the hospital and for everyone to contribute blood because I've never seen anything like this before."

Witnesses said that after the February 18 shootings, protesters in Benghazi continued on to the courthouse and gathered there throughout the evening, the crowd swelling to thousands.

In Baida, further to the east, protesters on February 18 buried the 23 people who had been shot dead the day before. One protester told Human Rights Watch that police were patrolling the streets but he had seen no further clashes.

In Ajdabiya, to the south of Benghazi, one protester told Human Rights Watch that early on February 18 people had gathered to bury the three protesters shot dead the day before. He said that on February 17, Revolutionary Guard officers fired upon peaceful protesters who were calling for a change in government. He said the protests were ongoing as of 9:30 p.m. on February 18 but that he had seen no further violence.

Tripoli, Libya's political and economic capital, remained quiet compared to the east of the country. Human Rights Watch spoke to the family of a man who had been summoned by Internal Security because of his postings on Facebook. On February 18 Internal Security officers came to the family's home at around 6 p.m. and took both the man and his uncle away with them to an undisclosed location.

"The Libyan government doesn't allow journalists and human rights monitors to work freely," said Stork. "But the world is watching what's happening, and abusive forces and their commanders can be held to account."