The violence is underpinned by Lebanon's deep sectarian divisions and the growing resistance to the port investigation by two Shiite Muslim parties: the powerful Hezbollah militant organization and its ally Amal Movement. Hezbollah stated that it will not be drawn into further violence.
Schools, banks, and government offices in Lebanon were closed Friday for a day to mourn, while funerals were held throughout the country.
Hezbollah members dressed in military uniforms paid their respects at a cemetery in Beirut's southern suburb. They stood before three coffins covered in the yellow flag of the group and decorated with white roses. Many women in black robes were present, as well as senior Hezbollah officials who gave speeches. For several minutes, mourners fired into the air.
An Amal fighter was also buried in southern Beirut.
The possibility of sectarian violence returning to a country that is already in the grips of one of the worst economic crises in 150 years was raised by the firefight.
Violence broke out during a demonstration organized by Amal and Hezbollah calling for the dismissal of the chief judge who was investigating the massive explosion that occurred at Beirut port last year. Officials from both sides have indicated that the judge's investigation will lead to them being held responsible for the explosion, which claimed the lives of at least 215 people.
Many of those protesting on Thursday were armed.
Ali Haidar, a Shiite 23-year-old, participated in the protest. He said that nearby residents started throwing rocks and bottles, then snipers on rooftops opened fire from two directions on protesters, leaving people stuck in middle.