SAN FRANCISCO (KRON) — A physical confrontation erupted between Donald Trump supporters and protesters Friday morning at the state’s GOP convention in Burlingame.

The controversial Republican party presidential frontrunner kicked off the two-day event at the Hyatt Regency San Francisco Airport at 1333 Old Bayshore Highway in Burlingame.

Police in riot gear stood shoulder-to-shoulder to keep demonstrators back as they were pelted with eggs. The crowd chanted anti-Trump slogans in a rowdy scene reminiscent of protests that grew out of hand following a Trump rally in Southern California the night before.

Protesters clashed with a supporter who was dressed in Trump’s signature red baseball cap emblazoned with the words “Make America Great Again.” One of the protesters is caught on video snatching the hat off the man’s head.

On Friday, a man wearing a Trump campaign “Make America Great Again” red hat was struck while being jostled by a group of shouting protesters.

“It went gangbusters. They attacked me,” said Chris Conway, a mortgage broker from San Mateo.

Burlingame city officials have called on dozens of police officers from agencies throughout San Mateo County to help with security. Trump’s campaign events are attracting large, and sometimes violent, demonstrations nationwide including Thursday night’s raucous rally in Orange County that led to 20 arrests.

Police are reporting five arrests and one minor injury during the large protests in Burlingame.

In Southern California, violent demonstrations led to 17 arrests as the Republican presidential contender brought his campaign to conservative Orange County on Thursday.

While Trump held a rally at a fairgrounds amphitheater, dozens waved anti-Trump signs outside in mostly peaceful protests and traded insults with masses of the candidate’s supporters who had lined up to see him. Later in the evening, however, the protests swelled and grew rowdy and spilled into the streets.

One Trump supporter had his face bloodied in a scuffle as he tried to drive out of the arena. One man jumped on a police car, leaving its front and rear windows smashed and the top dented, and other protesters sprayed graffiti on a police car and the Pacific Amphitheatre’s marquee.

Dozens of cars – including those of Trump supporters trying to leave – were stuck in the street as several hundred demonstrators blocked the road, waved Mexican flags and posed for selfies. Some protesters badgered Trump fans as they walked to their cars in the parking lot.

Police in riot gear and on horseback pushed the crowd back and away from the venue. There were no major injuries and police did not use any force.

Earlier in the evening, a half-dozen anti-Trump protesters taunted those waiting to get into the venue. Trump supporters surrounded one man who waved a Mexican flag and shouted “Build that wall! Build that wall!” – a reference to Trump’s call to create a barrier between the United States and Mexico to stop illegal border crossings.

Seven shirtless women wearing Bernie Sanders stickers over their breasts entered the square outside the amphitheater. They said they were protesting Trump’s lack of engagement on issues of gender equality and women’s rights.

“I feel like he wants to make America great again, but certainly not for women, for the LBGTQ community or for the lower class,” said one of the women, Tiernan Hebron, referencing the lesbian, gay, bisexual and transgender community. “He has, like, done nothing to help with gender equality or women’s rights or reproductive rights or anything.”

Trump has drawn large crowds across the country, with some of his events marred by protests and scuffles. The Pacific Amphitheatre was filled to its capacity of about 8,000 and a couple thousand more were turned away, Orange County Sheriff’s Lt. Mark Stichter said.

Earlier this week, a Trump rally in nearby Anaheim turned contentious when his supporters and protesters clashed, and several people were hit by pepper spray. Trump was not present.

KRON4 News crews are at the scene and have reporting skirmishes between both sides.

Stay with KRON4 News for continuing coverage live from Burlingame.