Violence erupted in Berkeley today when competing left and right wing groups clashed in Martin Luther King Park.
It was unclear which group announced their event first, but both were determined to rally in the park simultaneously.
Rich Black, who organized the March for Trump event at the same site last month, organized a coalition of right-wing groups under the aegis of The Liberty Revival Alliance. They were opposed by a left-wing coalition organized under the banner Defend the Bay.
The two sides assembled around 10 a.m at Martin Luther King Civic Center Park. White supremacist groups and Trump supporters clashed with a black block amidst tear gas, smoke bombs, and fireworks intermittently throughout the day.
According to the Berkeley Police Department Twitter account, 20 arrests were made.
Police made light-handed attempts to keep peace in the park but spent most of their time on the sidelines after their barricade broke.
Some ralliers lingered, but events were largely over shortly before 3 p.m. when the black bloc was forced to retreat.