TRIPOLI, Libya — Libyan militiamen opened fire Friday on white-flag-waving protesters demanding their disbandment, killing at least 31 people and wounding more than 200 in a barrage of heavy machine gun and rocket-propelled grenade fire.
Libyan Prime Minister Ali Zidan blamed the protesters and the militia alike for the violence, though witnesses said they saw no protesters carrying weapons ahead of the shooting Friday afternoon. By Friday night, however, some protesters joined by other militias had armed themselves and heavy gunfire rang out in the Tripoli neighborhood where the attack happened.
Armed groups set up checkpoints across the Libyan capital, hoping to stop other militias from entering the city. Ambulance sirens wailed into the night.
The march in Tripoli by thousands of protesters was the biggest show of public anger at militias in months. Since the 2011 fall of dictator Moammar Gadhafi, hundreds of militias — many of them on government payroll — have run out of control in Libya, carving out zones of power, defying state authority and launching violent attacks.
The protesters marched from a downtown mosque to a neighborhood called Gharghour, home to the headquarters of a militia originally from the city of Misrata that has a powerful presence in Tripoli. Many militias have turned villas and residential compounds of former Gadhafi-era officials into camps where they stash weapons
The demonstrators waved Libyan and white flags and chanted, "We want an army, we want police," referring to demands that the country's weak security forces take the place of militias.
When they neared the building, militiamen in civilian clothes and military uniforms came out of the headquarters, opening fire. Protesters ran from gunfire while carrying others covered in blood.
Libyan state television put the death toll at 31, with 235 people wounded.
Witnesses all said the protesters carried no weapons. Al-Taher Basha Agha, commander of Misrata-based militia, told Libya's private al-Ahrar television station that their rivals used the protesters as a cover to attack.
Prime Minister Ali Zidan also blamed both protesters and the militiamen for the violence in a televised news conference.
"You can't open fire at people who are exchanging fire," Zidan said.
Protesters said they were shocked by the prime minister's comments, pointing to an image of a bleeding elderly man shared on social media.
Libya's militias grew out of the informally created local brigades of rebels who battled Gadhafi's military. Since his fall and death, the government has turned to militias to keep the peace.
But government pay has not put them under state control. The armed groups — some of which include Islamic militants — act on their own agendas. Many of them carry out kidnappings, torture and targeted killings.
Al-Sadat al-Badri, the head of Tripoli's city council, called for three-day mourning in the capital while asking residents for "self-restraint."
The reaction was reminiscent of a similar scene last year in the eastern city of Benghazi, where thousands of protesters besieged headquarters of Islamic militias, forcing them to flee and clashed with others where dozens were killed. The protests came days after the killing of U.S. Ambassador Chris Stevens and three other Americans in a deadly attack on an American mission in Benghazi.
On Friday, the U.S. State Department said it had been quietly offering rewards since January of up to $10 million for information leading to the arrest or conviction of any person involved in the Benghazi attack.