Donald Trump spoke at the California Republican convection on Friday afternoon after hundreds of protesters tried to thwart him from entering the hotel where the event was being held.
Trump delivered the address at the convention's kickoff lunch. The sold-out convention, which runs through Sunday morning, is being held at the Hyatt Regency San Francisco Airport in Burlingame.
Dozens of protesters had already assembled outside the hotel by 9:30 a.m., video from the scene showed. A large police presence was also visible in the area, and the gathering appeared to be disrupting traffic.
Demonstrators linked arms and were sitting on the ground as they attempted to block entrance to the event, photos showed. Some chanted, "Shut it down!" as they blocked entry to the Hyatt.
The situation started escalating when protesters surrounded a Trump supporter who walked through the crowd as he tried to get into the hotel, pulling off his "Make America Great Again" hat, and punching and kicking him, according to the Los Angeles Times.
Several other physical altercations, including shoving, could be seen between protesters and police officers. Bare-breasted protesters, men and women, some of whom were associated with the progressive group Code Pink, chanted "Stop hate" as they marched.
By noon, a large crowd trying to thwart Trump from entering the Hyatt broke through the barriers outside the Hyatt and attempted to rush the hotel. They were followed by officers dressed in riot gear who pushed them away, clearing the way for Trump's arrival.
It was unclear whether any of the demonstrators were able to enter the Hyatt.
The scuffle prompted the GOP contender's motorcade to stop on the side of a nearby freeway, where Trump -- surrounded by security -- hopped a barrier and walked the rest of the way to the building, aerial video showed.
His speech was scheduled to start at noon, but was delayed as a result of the disruption. The candidate was backstage, the state GOP chairman told the awaiting crowd shortly after 12 p.m.
It began right before 1 p.m., with the candidate acknowledging the difficulty he faced in getting to the event.
“That was not the easiest entrance I’ve ever made,” Trump told the convention. “My wife called; she said, ‘There are helicopters following you.’ Then we went under a fence … Oh boy, felt like I was crossing the border, actually.”
Burlingame Police Lt. Jay Kiely said later Friday that five people were arrested, including one who was with the crowd when it tried to rush the Hyatt's entrance. One injury was reported, but Kiely did not know whether it was a police officer, protester or supporter who was hurt or the extent of the injury.
The drama unfolded one day after Trump's supporters and critics clashed outside a campaign event at the OC Fair and Event Center in Costa Mesa.
Seventeen people were arrested after a crowd of several hundred flooded into the streets near the Pacific Amphitheater following the rally's conclusion Thursday night, the Costa Mesa Police Department said Friday.
Amid the chaotic scene, one protester started jumping up and down on the roof of a Costa Mesa police vehicle, breaking out the rear window of the patrol car, aerial video showed. The front window was also smashed.
Several others swarmed as they attempted to overturn the vehicle before officers moved in.
No major injuries were reported by the Sheriff's Department, but one man wearing a Donald Trump T-shirt appeared to have been hurt and was placed into an ambulance, video from the scene showed.
Some 31,000 people attended the rally, with thousands more being turned away, Trump tweeted.
Trump calls for party unity
In his speech at the convention, Trump predicted the primary season would soon come to a close and called for Republicans to come together, stressing, "there has to be unity in our party."
But, he made sure to note, he could still win in November even if he fails to unite the party.
"Could I win without it? I think so, to be honest, I think so," he said. High-profile Republicans such as Jeb Bush, he continued, may not support him in the general, but he brushed that off as a minor issue. "Big deal, like I care. OK?"
"Again, ideally, we're going to be together," Trump said. "I think I will win even if we're not together. I mean there are some people, I honestly don't want their endorsement. I just don't want it ... It's not going to have any impact on whether or not we beat Hillary Clinton. It's not going to have any impact. But most of the party has to come together."
As he wrapped up his speech, Trump again mentioned the protests outside and the lengths to which he had to go to be there Friday afternoon.
"You have no idea the route they have planned for me to get out of here," Trump said.
The two other major remaining GOP contenders in the race, Ted Cruz and John Kasich, are also scheduled to speak at the state's Republican convention.
Kasich is set to talk at the dinner Banquet Friday night, while Cruz will deliver a speech at the lunch banquet Saturday.
KTLA's Melissa Pamer contributed to this story.