Lebanese security troops fired tear gas to disperse dozens of protesters who gathered late on Thursday in anger at Tuesday's blast, which is widely regarded as the most shocking example of the government's incompetence.
The scuffles in central Beirut took place in a ravaged street leading to Parliament with the wreckage from the explosion still littering the whole area.
The protesters sparked a fire, vandalised stores and threw stones at troops, the state-run National News Agency reported.
Police responded with tear gas to disperse the small but furious crowd, wounding some demonstrators, NNA reported.
Tuesday's blast killed at least 145 people, wounded at least 5,000 and destroyed entire districts of the capital.
Lebanese authorities said it was caused by a fire igniting 2,750 tonnes of ammonium nitrate negligently stored in a warehouse at Beirut's port since 2014.
This raised questions as to how such a huge cargo of the highly explosive substance could have been left unsecured for so long.
Lebanon was already mired in its worst economic crisis since the 1975-1990 civil war.
The blast added to the grievances of a protest movement that emerged in October to demand the removal of an inept and corrupt political class.
Activists have called for a large anti-government rally on Saturday for an event they call "Hang them by the gallows".