Libyan authorities retook control Saturday of the headquarters and bases of militias in Benghazi after armed protesters attacked them overnight in violence that killed at least 11 people and wounded more than 70.
Six members of the security forces were among those killed in the unrest that rocked Libya's second city, in the wake of the murder of US ambassador Chris Stevens and three other Americans on the anniversary of the 9/11 attacks.
The security force members appeared to have been executed, a medical examiner at the Benghazi Medical Centre morgue told AFP.
"From the nature of the wounds it is clear that the six were executed," she said on condition of anonymity, adding that all six were shot in the head.
"In total we've received 11 fatalities" she said, including four bodies in "civilian clothes" and another that was found at the headquarters of Raf Allah al-Sahati, an Islamist militia targeted overnight.
The violence erupted late on Friday when hundreds of protesters, some of them armed, attacked bases of paramilitary groups, former rebels who helped topple Moamer Kadhafi's regime in last year's rebellion.
Critics say militias in the eastern city have put themselves above the law, particularly those that refused to be placed under the authority of the defence ministry after the fall of the regime.
The protesters first attacked a group based in a security building in central Benghazi before turning their wrath on the headquarters of Ansar al-Sharia, a radical Salafist militia and the main paramilitary group in the city.
To shouts of "The martyrs' blood was not shed in vain," the demonstrators pushed into the compound which was pillaged and torched, an AFP correspondent witnessed.
Regular armed forces retook control of the two bases on Saturday, the correspondent said.
Ansar al-Sharia has been accused of -- but denied -- involvement in the murder this month of the four Americans in an attack on the US consulate in Benghazi on September 11.
The militiamen took flight as hundreds of protesters stormed and then set their compound ablaze. They also evicted them from Al-Jalaa hospital where they were replaced by military police, an AFP correspondent reported.
Protesters also attacked the headquarters of the Raf Allah al-Sahati brigade, an Islamist group under the authority of the defence ministry, on the city outskirts.
An AFP correspondent said the assailants walked away with weapons, ammunition and computers. After two hours of fierce fighting during which rockets were used, they managed to drive out members of the brigade.
On Saturday, Raf Allah al-Sahati said on its Facebook page that its militants had returned to their base.
Protesters also marched on four other militia bases overnight, forcing their occupants to flee.
LANA news agency quoted officials of the Martyrs of Abu Slim Brigade as saying they had decided to dissolve the militia and pull out of public buildings they had occupied in Derna, east of Benghazi, following demands by residents.
National assembly chief Mohamed al-Megaryef initially welcomed the Benghazi protest but later urged the demonstrators to withdraw from the bases of loyal brigades.
Megaryef was meeting military, tribal and political leaders in the city on Saturday, members of his entourage said.
As the violence expanded, Libyan authorities called on the demonstrators to distinguish between "illegitimate" brigades and those under state control, warning that neutralising loyal units risked causing "chaos."
The warning highlighted the dilemma facing the government a year after Kadhafi's overthrow, with the fledgling security forces dependent on former rebels who fought in the uprising although such groups also challenge government authority.
The trigger for the assault on the paramilitaries was a "Save Benghazi" rally after the main weekly Muslim prayers on Friday that was attended by an estimated 30,000 peaceful demonstrators.
They paid tribute to Stevens and carried banners calling for justice to be done.
It drowned out a smaller rally of a few hundred people called by the jihadists and hardline Islamists furious over a US-made film that mocks Islam and cartoons of the Prophet Mohammed published by a French satirical magazine.
The two sides gave conflicting accounts of what sparked the deadly violence.
"We came peacefully and asked them with our loudspeakers to disarm," said protester Nasser Saad.
But militiaman Ahmed Faraj insisted that the attackers were only after the base's armoury.
"They were coming to take our weapons," he said. "We are part of the ministry of defence, we fought in the revolution, we can't just walk away and hand over heavy weapons to a bunch of drunks and criminals."
"Now with the people calling for a hardline anti-militia policy, Libyan leaders may find themselves steeled with the requisite courage to purge these groups from the Libyan body politic," said Libya specialist Jason Pack.