Lebanon police fire tear gas at angry demonstrators
Protesters had sparked a blaze, vandalised stores and lobbed stones at security forces, according to the state-run National News Agency.
Police responded with tear gas to disperse the small, but clearly furious crowd, wounding some demonstrators, NNA said.
Tuesday's blast killed more than 150 people, wounded at least 5,000 and destroyed entire districts of the capital.
Lebanese authorities said it was triggered by a fire igniting 2,750 tonnes of ammonium nitrate negligently stored in a warehouse at Beirut's port since 2013.
Read more: Beirut Explosion: Be angry, not just sad, for Lebanon
This raised questions as to how such a huge cargo of the highly explosive substance could have been left unsecured for so long.
The explosion came as Lebanon was already knee-deep in its worst economic crisis since the 1975-1990 civil war.
It added to the grievances of a protest movement that emerged in October to demand the removal of a political class deemed inept and corrupt.
Activists have called for a large anti-government demonstration on Saturday - an event they have titled "hang them by the gallows."
Thursday's scuffles erupted as Lebanon's ambassador to Jordan resigned, saying "total negligence" by the country's authorities signalled the need for a leadership change.