BENGHAZI, Libya — Hundreds of protesters angry over last week’s killing of the U.S. ambassador to Libya stormed the compound of the Islamic extremist militia suspected in the attack, evicting militiamen and setting fire to their building Friday.

In an unprecedented show of public anger at Libya’s rampant militias, the crowd overwhelmed the compound of the Ansar al-Shariah Brigade in the center of the eastern city of Benghazi.

Ansar al-Shariah fighters initially fired in the air to disperse the crowd, but eventually abandoned the site with their weapons and vehicles after it was overrun by waves of protesters shouting “No to militias.”

“I don’t want to see armed men wearing Afghani-style clothes stopping me in the street to give me orders, I only want to see people in uniform,” said Omar Mohammed, a university student who took part in the takeover of the site, which protesters said was done in support of the army and police.

No deaths were reported in the incident, which came after tens of thousands marched in Benghazi against armed militias. One vehicle was also burned at the compound.

For many Libyans, the Sept. 11 attack on the U.S. Consulate in Benghazi was the last straw in one of the biggest problems Libya has faced since the ouster and death of longtime dictator Moammar Gadhafi around a year ago — the multiple mini-armies that with their arsenals of machine guns and rocket-propelled grenades are stronger than the regular armed forces and police.

The militias, a legacy of the rag-tag popular forces that fought Gadhafi’s regime, tout themselves as protectors of Libya’s revolution, providing security where police cannot. But many say they act like gangs, detaining and intimidating rivals and carrying out killings.

Militias made up of Islamic radicals like Ansar al-Shariah are notorious for attacks on Muslims who don’t abide by their hardline ideology. Officials and witnesses say fighters from Ansar al-Shariah led the attack on the U.S. consulate, which killed Amb. Chris Stevens and three other Americans.

After taking over the Ansar compound, protesters then drove to attack the Benghazi headquarters of another Islamist militia, Rafallah Sahati. The militiamen opened fire on the protesters, who were largely unarmed. At least 20 were wounded, and there were unconfirmed witness reports of three protesters killed.

Earlier in the day, some 30,000 people filled a broad boulevard as they marched along a lake in central Benghazi on Friday to the gates of the headquarters of Ansar al-Shariah.

“No, no, to militias,” the crowd chanted, filling a broad boulevard. They carried banners and signs demanding that militias disband and that the government build up police to take their place in keeping security. “Benghazi is in a trap,” signs read. “Where is the army, where is the police?”

Other signs mourned the killing of Stevens, reading, “The ambassador was Libya’s friend” and “Libya lost a friend.” Military helicopters and fighter jets flew overhead, and police mingled in the crowd, buoyed by the support of the protesters.

The march was the biggest seen in Benghazi, Libya’s second largest city and home to 1 million people, since the fall of Gadhafi in August 2011. The public backlash comes in part in frustration with the interim government, which has been unable to rein in the armed factions. Many say that officials’ attempts to co-opt fighters by paying them have only fueled the growth of militias without bringing them under state control or integrating them into the regular forces.

Residents of another main eastern city, Darna, have also begun to stand up against Ansar al-Shariah and other militias.

The anti-militia fervor in Darna is notable because the city, in the mountains along the Mediterranean coast north of Benghazi, has long had a reputation as a stronghold for Islamic extremists. During the Gadhafi era, it was the hotbed of a deadly Islamist insurgency against his regime. A significant number of the Libyan jihadists who travelled to Afghanistan and Iraq during recent wars came from Darna. During the revolt against him last year, Gadhafi’s regime warned that Darna would declare itself an Islamic Emirate and ally itself with al-Qaida.

But now, the residents are lashing out against Ansar al-Shariah, the main Islamic extremist group in the city.

“The killing of the ambassador blew up the situation. It was disastrous,” said Ayoub al-Shedwi, a young bearded Muslim preacher in Darna who says he has received multiple death threats because has spoken out against militias on a radio show he hosts. “We felt that the revolution is going in vain.”

Leaders of tribes, which are the strongest social force in eastern Libya, have come forward to demand that the militias disband. Tribal leaders in Benghazi and Darna announced this week that members of their tribes who are militiamen will no longer have their protection in the face of anti-militia protests. That means the tribe will not avenge them if they are killed.

Activists and residents have held a sit-in for the past eight days outside Darna’s Sahaba Mosque, calling on tribes to put an end to the “state of terrorism” created by the militias.

Militiamen have been blamed for a range of violence in Darna. On the same day Stevens killed in Benghazi, a number of elderly Catholic nuns and a priest who have lived in Darna for decades providing free medical services, were attacked, reportedly beaten or stabbed. There have been 32 killings over the past few months, including the city security chief and assassinations of former officers from Gadhafi’s military.

Darna’s residents are conservative, but they largely don’t fit the city’s reputation as extremists. Women wear headscarves, but not the more conservative black garb and veil that covers the entire body and face. In the ancient city’s narrow alleys, shops display sleeveless women dresses and the young men racing by in cars blare Western songs.

And many are impatient with Ansar al-Shariah’s talk of imposing its strict version of Islamic law. The group’s name means “Supporters of Shariah Law.”

“We are not infidels for God sake. We have no bars, no discos, we are not practicing vice in the street,” said Wassam ben Madin, a leading activist in the city who lost his right eye in clashes with security forces on the first day of the uprising against Gadhafi. “This is not the time for talk about Shariah. Have a state first then talk to me about Shariah.”

“If they are the ‘supporters of Shariah’ then who are we?” he said. “We don’t want the flag of al-Qaida raised over heads,” he added, referring to Ansar al-Shariah’s black banner.

One elder resident at the Sahaba Mosque sit-in, Ramadan Youssef, said, “We will talk to them peacefully. We will tell them you are from us and you fought for us” during the civil war against Gadahfi. But “if you say no (to integrating into the) police and army, we will storm your place. It’s over.”

Officials in the interim government and security forces say they are not strong enough to crack down on the militias. The armed factions have refused government calls for them to join the regular army and police.

So the government has created a “High Security Committee” aimed at grouping the armed factions as a first step to integration. Authorities pay fighters a salary of as much as 1,000 dinars, around $900, to join — compared to the average police monthly salary of around $200. However, the militias that join still do not abide by government authority, and critics say the lure of salaries has only prompted more militias to form.

Officials and former rebel commanders estimate the number of rebels that actually fought in the 8-month civil war against Gadhafi at around 30,000. But those now listed on the High Security Committee payroll have reached several hundred thousand.

“All these militia and entities are fake ones but it is mushrooming,” said Khaled Hadar, a Benghazi-based lawyer. “The government is only making temporarily solutions, but you are creating a disaster.”