BERKELEY, Calif. — A “Patriot Day” rally turned violent when hundreds of supporters and detractors of President Donald Trump met Saturday.

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A pro-Trump group had scheduled a rally at Martin Luther King Jr. Civic Center Park when a group opposed to the president said they were also going to meet at the park.

Fistfights ended up breaking out between members from both groups during morning and afternoon protests, according to the Los Angeles Times.

Berkley police arrested 13 people and seized prohibited items, including a flagpole, knife, stun gun and helmets, according to KABC.

Thousands of people across the country took to the streets in protest, some asking the president to release his tax returns, others to show support of the Trump administration.

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At least 20 were arrested.

Cox Media Group National Content Desk