UPDATE: 9:30 p.m., May 27, 2016
San Diego Police said 35 arrests were made during a protest Friday, when Donald Trump held a rally at the San Diego Convention Center:
**Final Update** 35 arrests were made today during the protest. No property damage was reported. No injuries were reported.
— San Diego Police (@SanDiegoPD) May 28, 2016
UPDATE: 7 p.m., May 27, 2016
Authorities say around a dozen people were arrested outside Donald Trump's rally in San Diego.
Police Chief Shelley Zimmerman said most people obeyed an order to leave the area outside the rally Friday afternoon after some protesters and supporters of the Republican candidate became unruly.
Officers in riot gear declared the gathering outside the downtown convention center unlawful after shouting matches erupted and people began hurling trash at each other. The two sides faced off after Trump supporters left the rally around 4 p.m.
Police shoved back demonstrators to keep the two groups apart.
Earlier, officers used batons to keep several protesters off a railing used as a barrier between protesters and the convention center.
UPDATE: 6:08 p.m., May 27, 2016
The majority of crowd had dispersed as of 6 p.m. with a "defiant few" left, San Diego Police Chief Shelley Zimmerman said Friday evening.
Some people threw rocks and bottles at police officers, said Zimmerman, adding that they have been trained for that situation.
UPDATE: 4:48 p.m., May 27, 2016
San Diego police said three people were arrested outside the San Diego Convention Center, where Trump held a rally Friday afternoon.
About a thousand people outside the facility, some clashing with law enforcement, remained after Trump's speech ended. Police declared an unlawful assembly around 4:30 p.m.
The majority of the crowd has been peaceful, according to 10News, but there have been reports of items being thrown. Officers have threatened to use tear gas if necessary.
"Due to violence and physical confrontation in the crowd (officers) are now moving into the area. Dispersal orders have been given," San Diego police said on Twitter.
UPDATE: 3:25 p.m., May 27, 2016
Trump on Friday addressed about 10,000 supporters at the San Diego Convention Center in his first campaign rally in San Diego as more than 1,000 people protested outside the facility, some clashing with police.
The presumptive Republican presidential nominee thanked local GOP Congressmen Darrell Issa of Vista and Duncan Hunter of Alpine before speaking for about an hour.
Trump said he would compete strongly for California's electoral votes in November. He addressed the Trump University lawsuit and President Barack Obama's visit to Japan. He also criticized Democratic presidential candidate Hillary Clinton and called her Democratic opponent Bernie Sanders "great."
"We're becoming a third-world country and it's not gonna happen any longer," Trump told his supporters.
A few protesters were thrown out during the rally.
UPDATE: 3:05 p.m., May 27, 2016
Police have made at least one arrest outside the San Diego Convention Center, where Trump is speaking to thousands of supporters.
Some protesters have thrown rocks at officers, who had to reorganize.
UPDATE: 2:38 p.m., May 27, 2016
Trump has begun speaking at a rally at the San Diego Convention Center. About 10,000 people have gathered to watch his speech, while over 1,000 protesters are outside the facility.
You can watch the rally on KPBS News partner 10News' website.
UPDATE: 1:45 p.m., May 27, 2016
Trump's private jet has landed at Lindbergh Field, prior to his rally at the San Diego Convention Center.
Thousands of supporters at the event have already heard remarks from former vice presidential candidate Sarah Palin, and local Republican congressmen Darrell Issa and Duncan D. Hunter.
UPDATE: 12:20 p.m., May 27, 2016
As of noon, no arrests have been made as thousands of supporters and opponents of Trump converge on the San Diego Convention Center, according to San Diego police Chief Shelley Zimmerman.
In Fresno, where the presumptive Republican presidential nominee spoke midmorning before his rally in San Diego, a largely young and Latino crowd chanted, held signs and marched around the arena where Trump spoke.
At one point a protester pulled at a gate but other demonstrators tried to calm him down. Police formed a line between the protester and the gate. Despite tense moments, there were no arrests by the time the rally ended.
Original post
Thousands of protesters and supporters of Donald Trump gathered around the San Diego Convention Center Friday morning hours before the presumptive Republican presidential nominee is scheduled to hold a campaign rally in San Diego for the first time.
Trump, who on Thursday reached the number of delegates necessary for the GOP nomination, will appear at the convention center at 2 p.m.
Numerous opposition groups, from organized labor to immigration advocates, planned to demonstrate outside the convention center.
Protests turned violent Tuesday in Albuquerque, leading to concerns about security in San Diego.
Several hundred protesters marched around the Fresno arena where Trump held a rally midmorning before his visit to San Diego.
Police Chief Shelley Zimmerman vowed that law enforcement will tolerate no violence, disruptive behavior or unlawful acts at the Trump event.
"For anyone who comes to disrupt, to do illegal activities, we will take swift and decisive action to make sure we have a peaceful event," Zimmerman told news crews Wednesday.
The department plans to have a "significant presence" of uniformed and plainclothes officers at Friday's bayside gathering and has coordinated with state, local and federal agencies to promptly put a stop to any combative or destructive protesters or counter-protesters, the chief said.
The city has designated demonstration zones — one for Trump supporters and another for those who oppose the 69-year-old billionaire real estate magnate's presidential bid — on the northwest and southeast sides of the Harbor Drive center and will strictly monitor attendees' behavior while ensuring their constitutional free-speech rights, Zimmerman said.
"And we are well prepared to respond," she said.
Seven adults and one juvenile were arrested outside a Trump rally Wednesday in Anaheim after some protesters hurled bottles at police and others tried to climb over a barrier. Police said that prompted officers to declare an unlawful assembly and begin attempts to disperse the crowd.
Protesters and supporters alike are encouraged to use public transportation to get to the event. The trolley system has a stop outside the convention center.
On Thursday, area Democrats slammed Trump in a conference call with reporters.
Rep. Scott Peters, D-San Diego, described the businessman as "dangerous" and "out of touch" with hard-working families.
Peters also accused Trump of having rooted for the recession-era housing slump so he could make a profit, opposing the minimum wage, lacking in foreign policy experience and relying on "misinformed ideas" about other countries.
"He is dangerous, he is divisive, and he is a demagogue, while Californians are tolerant and inclusive," Peters said. "We don't think it's fine to call Mexican immigrants 'rapists' and 'drug-dealers,' and we don't think it's fine to ban an entire religion from entering our country."
Former Assemblyman Nathan Fletcher criticized Trump's statements regarding veterans, and San Diego County Democratic Party Chairwoman Francine Busby said he would be "a disaster" for women and seniors.
Speaking in North Dakota Thursday, Trump announced his "America First" energy plan in which he said "American energy dominance will be declared a strategic economic and foreign policy goal of the United States."
He said his plan would remove bureaucracy from energy innovation and wean the country off energy imports.