During and after the war, thousands of rebels who fought Gadhafi formed "brigades" which the new government later used to fill a security vacuum until the national army and police could be rebuilt. Over time however, the units turned into militias, expanding in power and size and putting pressure on the fledgling government and parliament.
Tuesday's protest was the latest show of public outrage against armed groups since Friday's deadly shootings, which happened outside the headquarters of a militia from the western city of Misrata. It had deployed to Tripoli to battle Gadhafi's forces but later took over residential areas, villas and camps. Since the killings, some militias from outside Tripoli have left the city under public pressure.
On Monday, Zidan flew to Misrata for talks with city council officials and militia commanders, according to privately owned al-Nabaa TV. There were unconfirmed reports he was forced out of the meeting after disgruntled militiamen gathered outside the building.
Misrata militias and other militias in Tripoli accuse rival political and armed groups of orchestrating the demonstrations and firing at the protesters to turn public opinion against them. They describe the army troops that swept into the capital on Monday as remnants of Gadhafi's forces and denounce the move as "coup" against the revolution.
Adel al-Tarhouni, leader of a militia umbrella group Zidan accuses of involvement in his abduction last month, told The Associated Press that Gadhafi loyalists were trying to take over the capital and that the coming days will be "decisive," anticipating more violence ahead. His group, called The Revolutionaries Operation Room, is loosely affiliated with the Defense Ministry.
"These troops that were deployed are Gadhafi's brigades but under the independence flag," he said by telephone, referring to Libya's tricolor post-Gadhafi flag. He accused a parliamentary bloc led by former rebel Prime Minister Mahmoud Jibril of sending the troops to take over the capital.
Tripoli-based lawyer and former government official al-Saghir al-Maghri described the accusations as "ridiculous." He said the Defense Ministry had made it clear that the troops moved into Tripoli worked for the government and had been trained inside and outside Libya over the past months.
He said that militias from Misrata but also other cities like Gharyan were not withdrawing from the capital but only relocating, moving to inside camps run by the Chief of Staff. He expects more protests at the new locations.