Berkeley police say 13 people have been arrested after violence broke out Saturday between groups of supporters and detractors of President Donald Trump holding rallies in downtown Berkeley.
They say demonstrators left Berkeley's Martin Luther King Jr. Civic Center Park and are blocking several streets in the city's center.
About 200 people were at the park when some started pushing each other. Dozens of police officers in riot gear were standing nearby and quickly arrested one man. Others were arrested as several fistfights broke out.
Officials say officers have confiscated knives, flagpoles, helmets and sticks with signs on them among other things that were being used as weapons.
Photographs of the scene published online show at least two men with bloodied faces.