Libyan security forces killed at least 15 mourners and injured dozens of others at a funeral on Saturday, according to hospital officials.
The snipers targeting protesters against longtime ruler Moammar Gadhafi began firing on crowds as they mourned 35 people who died the previous day in anti-government rallies.
The shootings reportedly occurred in the eastern city of Benghazi, which has been a focal point of five days of unrest and where government forces wiped out a protest encampment earlier in the day.
New York-based Human Rights Watch previously reported that Libyan security forces have killed 84 people in a harsh crackdown on three days of protests. The latest reported fatalities from Saturday's funeral raise that death toll to about 100.
The protests calling for the removal of Gadhafi, Libya's leader for the past 42 years, have erupted largely in the cities of the country's impoverished east and have been brutally suppressed with a combination of armed militias and elite forces.
"The Libyan authorities should immediately end attacks on peaceful protesters and protect them from assault by pro-government armed groups," Human Rights Watch said in its statement.
Internet service was also cut off in Libya in the early hours of the morning on Saturday, according to the U.S.-based Arbor Networks security company, which detected a total cessation of online traffic in the North African country just after 2 a.m. local time.
In effort to combat anti-government protests of its own in January, the Egyptian government also cut off the Internet for several days, though it did not quell the uprising that eventually brought down the president.
On Friday, hundreds of Libyans loyal to Gadhafi also took to the streets in Tripoli, the country's capital, waving green flags and carrying signs supporting the leader.
At least five cities of eastern Libya have seen protests and clashes in recent days. In one of them, Beyida, a hospital official said Friday that the bodies of at least 23 protesters slain over the past 48 hours were at his facility, which was treating about 500 wounded -- some in the parking lot for lack of beds.
Military forces on Libya streets
Forces from the military's elite Khamis Brigade moved into Benghazi, Beyida and several other cities, residents said. They were accompanied by militias that seemed to include foreign mercenaries, they added.
Several witnesses reported French-speaking fighters, believed to be Tunisians or sub-Saharan Africans, among militiamen wearing blue uniforms and yellow helmets.
The Khamis Brigade is led by Gadhafi's youngest son Khamis Gadhafi, and U.S. diplomats in leaked memos have called it "the most well-trained and well-equipped force in the Libyan military."
The witnesses' reports that it had been deployed could not be independently confirmed.
The government has made an apparent gesture aimed at easing protests. The news website Quryna, which has ties to Seif al-Islam Gadhafi, another of the leader's sons, said Friday that the country's national congress has halted its session indefinitely and said many state executives will be replaced when it returns.
In addition to replacing top officials, it will endorse reforms to decentralize and restructure the government, it said.