The weekend fighting broke out after residents confronted Support Unit No. 8 militia for allegedly kidnapping and torturing two residents, The Washington Post reported Sunday.
The confrontation sparked a gunbattle between the militia and the Tripoli Supreme Security Committee, a union of several militias that run the capital's security operations.
The Support Unit No. 8 militia had been under the umbrella of the committee, but its legitimacy in the larger organization was revoked Sunday.
"The problem is that the revolutionaries still think they're revolutionaries, not employees who march to orders," said Mohamed Abu Shkiwa, an official with the Tripoli Supreme Security Committee.
Shkiwa said his forces were aware of three people injured in the clash, though it was not reported from which side of the fight. Some residents said they thought the son of a rogue militia commander had been killed in the fight, the Post reported.