SAN DIEGO - Confrontations between protesters and police erupted in San Diego Friday after presumptive Republican presidential nominee Donald Trump promised thousands of supporters that he would offer a strong challenge for heavily Democratic California's electoral votes in the general election.
As Trump delivered an energetic, 58-minute speech inside the San Diego Convention Center, more than 1,000 protesters representing various opposition groups demonstrated outside.
The protests were mostly peaceful before the speech, but some who later tried to scale a barricade were turned back by police. Police said one person was arrested as a result.
After the speech, several confrontations disrupted what had been an orderly dispersal outside the convention center, and at least two others were arrested, according to police. Since that total was provided, several other people were seen being placed into handcuffs.
Some people in the crowd eventually started throwing things, prompting police to declare an unlawful assembly and begin moving people out of the area. Police in riot gear maintained a huge presence as the crowd moved into the Gaslamp Quarter.
In his speech, Trump said he can compete in California because people are tired of political leaders like "crooked Hillary" Clinton, the former first lady and secretary of state who is leading the delegate count in the race for the Democratic nomination. They offer "all talk and no action," he said.
He also said U.S. political leaders were "grossly incompetent."
"We're going to play for California, we're going to win California, you watch," Trump said.
On Thursday, Trump reached the number of delegates necessary for the GOP nomination.
"We have created a movement -- it's a movement to common sense, to smarts, we're not going to be ripped off anymore," Trump said.
He touched on numerous issues in his speech, touting his commitment to helping veterans, rebuilding the military and forcing allied nations to stop "abusing us."
He also went on rants over a class-action lawsuit filed against him and his now-defunct Trump University, which is scheduled to go to trial in November in San Diego, and a woman who worked for him but later made critical remarks about him to the media.
In a city close to the U.S.-Mexico border, he made only a couple of passing references to his plans to construct a wall that would keep illegal immigrants from entering the country.
Immigration activists joined organized labor and other groups to march to the convention center and demonstrate outside. Some carried Mexican flags and chanted profanities.
Protests turned violent Tuesday in Albuquerque following a Trump appearance, leading to concerns about security in San Diego and prompting police Chief Shelley Zimmerman to vow that law enforcement will tolerate no violence, disruptive behavior or unlawful acts at the Trump event in her city.
"The safety of our public is paramount," Zimmerman said. "The whole goal is to provide a safe environment for everyone."
The department had a "significant presence" of uniformed and plainclothes officers at the bayside gathering and coordinated with state, local and federal agencies in hopes of promptly putting a stop to any combative or destructive protesters or counter-protesters, the chief said.
The city designated demonstration zones -- one for Trump supporters and another for those who oppose the 69-year-old billionaire's presidential bid -- on the northwest and southeast sides of the Harbor Drive center and monitored attendees' behavior while ensuring their constitutional free-speech rights, Zimmerman said.
In the protest area, Martha McPhail of La Mesa held a "Dump Trump" sign.
"I am opposed to the hateful, bigoted, racist language of Donald Trump and his arrogance and intolerance," McPhail told City News Service. "I'm for all of our people -- all races, sexes, genders, military veterans -- and he's divisive."
Bryan Sanders, a Tucson resident, said he came to San Diego because Trump needs to be stopped.
"Donald Trump is a fascist," said Sanders, 33. "He has no business being in American politics. He's un-American. His march toward power needs to stop, and it's gonna."
Sanders said he was injured at a previous Trump rally in his hometown.
Riley Hansen, a 19-year-old supporter, was selling pro-Trump T-shirts and said he likes the candidate's business knowledge.
"My dad always told me you need a businessman as president," the Orange County resident said. "I like his policies. We need the border wall built."
Tami Eshelman of Lake San Marcos said she came to hear Trump speak and to show her support. She said she wants to find out who would serve on his team, such as cabinet members, if he's elected.
Former vice presidential candidate Sarah Palin, and area GOP Reps. Duncan D. Hunter and Darrell Issa warmed up the crowd, eliciting boos when they mentioned the media or President Barack Obama's visit to Hiroshima, Japan, the city where the first atomic bomb was dropped near the end of World War II.
Trump welcomed them and a large group of veterans to the stage at the beginning of his speech.
A campaign spokesman said about 20,000 people RSVP'd for the event, but the room at the convention center had a capacity of 10,000. A large number of people were still in line trying to get inside the facility as Trump delivered his speech.
Many of the people who had protested before the rally were gone by the time the post-speech crowd became unruly.
Law enforcement officers from several agencies cleared the Gaslamp Quarter and herded several hundred people onto Harbor Drive as a police helicopter ordered people to disperse.
Some waved Mexican flags while others staged a sit-in near the trolley tracks.
The Metropolitan Transit System stopped running through the area, and shuttled passengers south from the Santa Fe Depot.
Reporters in the area said a few people were pepper-sprayed, but it was unclear by whom.