The clashes broke out after gunmen shot hundreds of people heading for a protest against the lead judge in the investigation, organized by the militant group Hezbollah and supporters, according to media reports.
At least six people died and more than 30 were injured. Nine suspects were reportedly arrested.
Lebanon continues to grapple with numerous challenges, including economic and financial collapse, political stalemate, and the devastating long-term impact of the port explosions, which killed more than 200 people. No one has been found responsible yet.
The UN special coordinator for Lebanon, Joanna Wronecka, issued a statement condemning the violence on Thursday.
Noting the “dangerous increase in polarization” surrounding the investigation, he underscored the ultimate responsibility of Lebanese leaders to put the interests of the country first at this critical juncture.
“Bringing Lebanon out of its current crisis and advancing reforms requires the efficient functioning of the state’s legislative, executive and judicial institutions,” said Ms Wronecka.
Judicial independence key
“Now is the time for all parties to support judicial independence in the interests of the people,” he added.
The Special Coordinator also reiterated the UN’s unwavering support for the country and its people.