The scene outside a Donald Trump campaign rally in the San Francisco Bay Area apparently got out of hand on Thursday night.

Some anti-Trump protesters appeared to taunt people who attended the event at the San Jose Convention Center — at times shouting down attendees who were passing by. Reporters on the ground indicated that many of those attacked were Trump supporters.

A woman was hit with an egg:

Protestors are getting out of hand #DonaldTrump pic.twitter.com/Rxica3eMuB — Courtney Bennett (@courtbmedia) June 3, 2016

One man was apparently bloodied. That exchange was caught on video:

NOW: #Trump supporter attacked and left bleeding in San Jose pic.twitter.com/kC2GVz9JcZ — Tim Pool (@Timcast) June 3, 2016

Others appeared to be followed by the crowd and then ambushed:

I called 911 but no one answered. Donald trump protest in San Jose, CA pic.twitter.com/LwaWyeYZfq — Marcus DiPaola (@marcusdipaola) June 3, 2016

Some of the anti-Trump protesters declared "no room for hate in the 408," referring to a San Jose area code:

"In the 408 no hate:" Trump protesters stage mini protest at #SanJose rally. pic.twitter.com/PxgZhbBuT3 — Riya Bhattacharjee (@loislane28) June 3, 2016

Others chanted "no hate in our state:"

San Jose Police chief Eddie Garcia told reporters at a press conference Friday afternoon that at least four people were arrested. "What happened last night was disgraceful," Garcia said, adding that the violence "will not go unchecked," and saying that video evidence from the incident was being reviewed.

The police chief said that roughly 250 police officers were on scene during Thursday night's unrest, but acknowledged that more help was needed.

California rallies for Trump, the presumptive Republican presidential nominee, have largely been upended by groups of protesters opposing his candidacy.

View photos San Jose Trump protests More

The state boasts one of the largest Latino populations in the US, and it is the first large state without a white plurality, according to state officials cited by the Los Angeles Times. Among other things, that has made Trump's controversial immigration platforms deeply unpopular in the state.

"At some point Donald Trump needs to take responsibility for the irresponsible behavior of his campaign," San Jose Mayor Sam Liccardo told The Associated Press.

John Podesta, the Hillary Clinton campaign chair, tweeted: "Violence against supporters of any candidate has no place in this election."

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