On Friday, a peaceful anti-militia demonstration in the capital turned violent.
The violence broke out when gunmen opened fire on hundreds of protesters carrying white flags in the southern district of Gharghour, where the Misrata militia has its headquarters.
The Libyan government declared the state of emergency after another person was killed and dozens more were injured in similar clashes in Tripoli’s eastern suburb of Tajuraon on Saturday.
Local authorities have announced a three-day general strike in response to the recent spell of violence.
Thousands of protesters gathered in the city center to remember those killed on November 15.
The government has declared three days of mourning. It has also appealed for restraint, with Libya’s Prime Minister Ali Zeidan calling for a ceasefire and urging all militias to leave Tripoli.
Meanwhile, the United Nations Support Mission in Libya (UNSMIL) has urged an immediate end to the bloodshed.
Nearly two years after the fall of former dictator Muammar Gaddafi in a popular uprising, Libya is still plagued by lawlessness and insecurity, with armed groups flexing their muscles.
Over the past few months, Tripoli and its suburbs have been hit by violent clashes between rival militias who participated in the 2011 uprising.
Residents of Tripoli frequently demonstrate against militias. The former rebels refuse to lay down their arms, despite efforts by the central government to impose law and order.