The Berkeley, California police have detained 13 people, as a group of anarchists chased away right-wing demonstrators and attacked reporters near Martin Luther King Jr. Civic Center Park, according to local media.
One of the detentions was made on suspicion of assault with a deadly weapon, but the majorities were carrying banned items, the SFGate outlet reported on Sunday, citing police spokeswoman Jennifer Coats.
The number of arrests was revised down from 14, previously suggested by the police.
The police briefly detained Joey Gibson, the leader of the conservative group Patriot Prayer, who canceled a Saturday rally in San Francisco, but the detention was reportedly made to save him from demonstrators chasing after him, Sputnik reported.
On Saturday, crowds gathered in San Francisco to celebrate the cancelation of a Patriot Prayer event.
The California demonstrations took place only two weeks after a far-right rally in Charlottesville, Virginia, ended in tragedy, as a car rammed into a crowd of counter-protesters, killing one woman.