Many are rooted in particular cities or tribes but have extended their power geographically. The militia from Libya's third largest city, Misrata, for example, is a feared powerhouse in the capital, Tripoli, as is the militia from the western Zintan region - and the two are rivals, each backing one of the two main opposing blocs in parliament. In the country's eastern half, some militias have rallied behind calls for autonomy for the region, known as Cyrenaica, which has long complained of discrimination by Tripoli.
Others are rooted in ideology, particularly the array of hard-line Islamist militias, many of them inspired by al-Qaida.
Former parliament member al-Tawati al-Eiydha says militiamen have abducted a number of lawmakers, then stripped, humiliated and photographed them as blackmail to keep them in line.
He told The Associated Press he met with one victim who described his ordeal - a lawmaker he refused to identify. He said he investigated further and found "a second, a third and a fourth who were exposed to such treatment."
"Then I understood why those calling for asserting state control over militias were silenced," al-Eiydha said.
Al-Eiydha, a representative from the southern city of al-Kufra, first went public with his allegations several months ago on the Libya First TV network. In response, parliament voted him out of his seat.
Another former lawmaker, Mohammed Domaa, confirmed to the AP that the same parliamentarian described his abduction to him as well. The victim told Domaa that he was held for nearly a week by a militia on a "morals crime" and was tortured and photographed.
"He was in a state of nervous breakdown," said Domaa, who soon after being told of the incident resigned in protest over the abductions and the polarization in parliament.
"We wanted the rule of law, we wanted the state to have the exclusive use force. But what we got is militias with power concentrated in their hands," he said.
The militias' undermining of state authority is clear across the country.
The past two years, militias have assassinated some 200 prominent figures, including top police officials, prosecutors, judges and activists, mostly in the eastern region, particularly in Benghazi and Darna, a stronghold of Islamist militias.
Salah, the researcher, said investigators don't dare go to crime scenes or make arrests, and witnesses rarely testify for fear of retaliation. Courts have been shut down because judges fear assassination.
"There is a breakdown in law and order in many areas of Libya," said Salah.
In the city of Darna, the government has no authority at all in the face of multiple Islamic extremist militias seeking to establish rule by a strict interpretation of Shariah.
On Friday, militants paraded around the city in dozens of pickup trucks mounted with weapons, flying black jihadi banners. The group, the Shura Council of the Youth of Islam, declared on its Facebook page that it would defy "all infidel law" and only implement Shariah. It set up checkpoints in the city and said it was forming committees to resolve disputes among residents by Islamic law.
Darna sees frequent violence. During nationwide voting in February for an assembly to write a constitution, balloting in Darna had to be shut down completely because miltias bombed or blockaded polling stations. Over the past months, a former city prosecutor was gunned down, bodies of foreigners have been dumped in the streets, and gunmen attacked the city's treasury office, from which the government gives police their salaries.
Hanan al-Bereik, a Darna lawyer, said residents held a three-day sit-in demanding the government get rid of militias, but authorities did not respond.
"They want an Islamic state ... but all people reject this," al-Bereik said of the militias. "Women live in terror. There is no way they can walk out at night ... We fear for our children."
A dramatic attempt by an eastern militia to illegally sell a shipment of oil left Libyans stunned by their government's powerlessness. The attempt was thwarted only when a U.S. warship halted the tanker off Cyprus. The milita has controlled most of the country's oil facilities since last year, shutting down production in a further embarrassment to the government, though it recently reached an agreement to hand them back over.
"The country has nothing ... People are fed up," Gomaa Barbash, an airline company employee, said while sipping coffee in a Tripoli cafe.
"We want a president."
