Dozens gathered in Plaza Italia but were soon dispersed by water cannon. Police detained 21 demonstrators, citing rules against gatherings intended to prevent the spread of coronavirus.
Protesters threw blunt objects and sticks at the water cannon trucks. Public transport in the surrounding area was cancelled but vehicles were allowed free passage.
Protests over deep-rooted inequality erupted last year in October over a hike in metro fares. More than 30 people died, 3,000 were injured and 30,000 were arrested during the demonstrations.
The pandemic had all but silenced the masses that once turned out on a near nightly basis. Until Friday, only isolated disturbances had been reported following five months of quarantine.