Four Libyan protesters were killed and 20 wounded in Benghazi when gunfire erupted at a demonstration outside a militia base in the eastern city, security and medical sources said Saturday.
"Angry citizens, some of whom were armed, demonstrated around the headquarters of the February 17 Martyrs Brigade," an Islamist militia accused by residents of being involved in attacks across Benghazi, a security official said.
A gunfight broke out between the two sides late on Friday and continued until early Saturday, leaving several people dead and wounded, witnesses said.
A security source said all the casualties were protesters.
Four bodies were brought to the Benghazi Medical Centre, a source at the hospital said, as well as 16 people with gunshot wounds.
Another four wounded were taken to Al-Jala hospital, a medical source said.
Benghazi was the cradle of the 2011 uprising that ended Moamer Kadhafi's four-decade rule and has since been plagued by violence that has killed dozens of members of the security forces, judges and foreigners.
The latest demonstration took place the day after gunmen murdered the head of general intelligence for eastern Libya.
Colonel Ibrahim al-Senussi Akila was shot dead near the Medical Centre in the city centre on Thursday.
Libya's central authorities have struggled to assert their control over the vast, mostly desert country, which is effectively ruled by a patchwork of local militias and awash with heavy weapons.
In March, the authorities acknowledged for the first time the existence of "terrorist groups" in Libya, particularly in Benghazi and in Derna, an eastern city with a history of Islamist militancy.