Donald Trump supporters leaving the presidential candidate's rally in San Jose were pounced by protesters, some of whom threw punches and eggs.
Trump hats grabbed from supporters were set on fire on the ground. One least one woman was pelted with an egg. Police stood their ground at first but after about 90 minutes moved into the remaining crowd to break it up and make arrests. At least four people were taken into custody, though police didn't release total arrest figures Thursday night. One officer was assaulted, police Sgt. Enrique Garcia said. There were no immediate reports of injuries and no major property damage, police said. The crowd, which had numbered over 300 just after the rally, thinned significantly as the night went on, but those that remained near the San Jose Convention Center were rowdy and angry.
Police were keeping their distance from the crowd as the scuffles played out, but keeping them from getting any closer to the convention center.
The mayor, a Democrat and Hillary Clinton supporter, criticized Trump for coming to cities and igniting problems that local police departments had to deal with.
Such protests are unlikely to be repeated on Friday when Trump holds a rally at the airport in the much smaller and more conservative city of Redding about 150 miles north of Sacramento.
Clinton and Democratic opponent Bernie Sanders will also make campaign stops in the state on Friday in California as they look to Tuesday's California Primary.
Trump, the presumptive GOP nominee, spoke for about 50 minutes at the rally, sniping at Democratic candidate Hillary Clinton and calling her speech on foreign policy earlier in the day "pathetic" and "sad to watch."
Protesters included Adam Rivas, a 22-year-old community college student who was born and raised in San Jose, was holding a spray-painted sign that read "Dump Trump."