"We're going to review any surveillance video recordings from the area, as well as videos the public sends in to us, and perhaps send out arrest warrants for those people as well", Berkeley police spokesman Byron White told CNN. Officers on Saturday confiscated sticks, knives, flagpoles and helmets and sticks with signs on them.
Close to 11 people were injured in the skirmishes and some of them were taken to hospital for treatment.
The moment a man identified as Nathan Damigo punches an unidentified woman at a protest in Berkeley, Calif. on April 15, 2017. Tear gas and pepper spray was used.
Hundreds of Trump supporters had gathered at the Martin Luther King Jr.
For the third time this year, Trump supporters and Antifa clashed on the streets of Berkeley, California.
"Well, they want to hit me with brass knuckles from my blind side", Trump supporter John Beavers of Washington said, as his nose gushed blood.
But what may distinguish this event from the previous two street battles, in which pro-Trump students were beaten up by anti-Trump students and an global masked terrorist group called Antifa, was that the local Trump activists had out of state supporters who were ready for a fight.
Fistfights broke out, and protesters used pepper spray, metal pipes, lumber, bricks and other items that were prohibited for Saturday's protests.More news: Parent: Slain teacher's life was all about kids
We made a decision to show up anyway because this is our livelihood, said Tim Mueller, a farmer who owns the stall, surrounded by protesters on both sides.
About two dozen police officers showed up at the park early Saturday and set up a narrow entrance to control access.
Celebrities and lawmakers joined a Tax Day demonstration in New York City, where protesters planned to march to Trump Tower to demand that President Donald Trump release his tax returns.
The unrest underscores the heightened political tensions that have taken hold since President Trump took office in January. In February, a scheduled appearance by conservative provocateur Milo Yiannopoulos was canceled amid a violent protest at the University of California, Berkeley.
Among their placard messages: "Prove you have nothing to hide", "Donald Ducks his Fair Share", "No 1040, no peace" and "I pay for your golf trips".
At least 100 people from both camps eventually moved out of the park and continued fighting in the city's streets.
The demonstrations came just days before Tuesday's deadline for taxpayers to file their returns.