Steph Solis

USA TODAY

San Diego police arrested 35 protesters Friday outside a Donald Trump rally after a peaceful demonstration devolved into chaos, according to police.

Three hours into the calm protests, which drew up to 1,000 people, a number of demonstrators tried to breach an off-limits area, resulting in arrests, the police department said on Twitter.

Officers used batons to keep several protesters off a railing used as a barrier between them and the convention center where Trump was speaking, the Associated Press reported.

Then shouting matches erupted between protesters and Trump supporters as rallygoers left the center around 4 p.m. local time. The two sides began throwing trash at each other, and officers showed up in riot gear to push them apart, AP reported.

Radio station KFMB shared video of officers pepper spraying people.

Shortly after, police said the protest became unlawful. "An unlawful assembly has now been declared," San Diego police tweeted. "It is illegal to remain in the area."

Police ordered people to disperse and made arrests, citing violence and physical confrontations in the area. No property damage or injuries were reported, police said.

San Diego was one of two Californian cities where Trump, the presumptive GOP nominee, spoke Friday ahead of the state's June 7 primary.

Demonstrations formed in Fresno as well. AP reported 300 people planned to protest Trump's visit to the region, which has a large Latino population.