Sixty-five people were arrested after a crowd gathered Union Square turned violent Friday, the NYPD said.

According to NYPD Chief of Department Jeffrey Maddrey, the crowds gathered after a social media influencer, identified by the Associated Press as Kai Cenat, posted that he was giving away gaming systems and other prizes.

The NYPD called a mobilization of officers after crowds “overran” the park and the surrounding streets, and continued to increase the mobilization as crowds increased, Maddrey said.

The crowd swarmed around the influencer when he arrived at the park, Maddrey said at the briefing.

According to Maddrey, the gathering was declared an “unlawful assembly” when individuals began to commit acts of violence toward the police and public.

Maddrey said some of the members of the crowd broke into a construction site in the park and began to throw paint cans, rocks and bottles from the site at police, and were also walking around with axes and shovels.

Maddrey added that there was destruction of vehicles, food carts and stores, and fireworks were also lit and thrown at other members of the crowd and at the police.

According to Maddrey, the NYPD offered “multiple opportunities” and “multiple warnings” for the crowd to leave before making arrests.

Thirty juveniles were among the 65 people arrested, Maddrey said. The chief of department added that a city bus filled with people who were arrested was attacked, with people trying to pull people off of it. Police had to be sent to protect the bus, Maddrey said.

Maddrey said at least three police officers were injured. Two officers were removed via ambulance, and another sergeant suffered a broken hand, he said. At least four civilians were taken to area hospitals, he added. But he also added that he saw multiple other people with cuts, bruises and lacerations at the scene.

“We’re not against young people having a good time. We’re not against young people gathering. But it can’t be to this level where it’s dangerous. A lot of people got hurt today,” he said.

The influencer was removed to safety by police, according to Maddrey. Cenat was issued a desk appearance ticket Friday night after being released by the NYPD. Police say he is facing two counts of inciting a riot and unlawful assembly.

Cenat, 21, is a video creator with 6.5 million followers on the platform Twitch, where he regularly livestreams. He also boasts 4 million subscribers on YouTube, where he posts daily life and comedy vlogs ranging from “Fake Hibachi Chef Prank!” to his most recent video, “I Rented Us Girlfriends In Japan!”

His 299 YouTube videos have amassed more than 276 million views among them. In December he was crowned streamer of the year at the 12th annual Streamy Awards.

The Associated Press said messages sent to his publicist, management company and an email address for business inquiries were not immediately returned.

Livestreaming on Twitch from a vehicle as the event gathered steam, Cenat displayed gift cards he planned to give away. Noting the crowd and police presence, he urged, “Everybody who’s out there, make sure y’all safe. ... We’re not gonna do nothin’ until it’s safe.”

Eventually he and an entourage got out of the vehicle and hustled through an excited crowd, crossed a street and went into the park, where Cenat was at the center of a cheering, shoving mob.

Maddrey said the NYPD will review the incident to determine how the department monitors social media and how it can improve its response to similar events in the future.

“We have encountered things like this before, but never to this level of dangerousness where young people would not listen to our commands,” he said. “We were defending ourselves and we had to make arrests.”

Representatives of AMP, the YouTube group Cenat is a member of, sent a statement to NY1 Saturday evening saying “members” of the group were hoping to create a “positive experience” for fans and show appreciation for them.

“We’ve hosted fan meet ups and video shoots in the past, but we’ve never experienced anything at the scale of what took place yesterday. We recognize that our audience and influence are growing, and with that comes greater responsibility,” the AMP representative said. “We are deeply disheartened by the outbreak of disorderly conduct that affected innocent people and businesses, and do not condone that behavior.”

Information from the Associated Press was used in this report.