Every year, the New York radio station’s Hot 97 Summer Jam show is one of rap’s biggest events. Yesterday, the show once again came to New Jersey’s MetLife Stadium. But this time, things turned ugly when the New Jersey State Police clashed with people trying to get into the show. Around 7PM, possibly because of a fight between concertgoers, security closed the gates to the show and refused to let anyone in, including a number of people who had paid hundreds of dollars for tickets, as Asbury Park Press reports. When people massed outside the entrance, some knocked over barricades or threw bottles. Soon afterward, police showed up in full riot gear, taking a defensive formation. They eventually brought in an armored vehicle that emitted a loud, piercing, high-pitched alarm, and they also fired tear gas into the crowd. Many in the crowd were arrested, though no definite number has been released, and at least one was maced and pepper-sprayed.

On their Facebook page, the New Jersey State Police issued this statement:

This evening, security personnel at one of the entrance gates to MetLife Stadium were confronted by crowds attempting to illegally enter the sold out Summer Jam concert by climbing over fences and forcing their way through security personnel. The gates have been shut and troopers on site have called for assistance from several nearby stations to help maintain order.

Troopers and stadium security officials are insisting that all people outside of the gates depart the MetLife grounds to avoid congestion when the concert lets out. There is no number of arrests available at this time.

A spokesman for Emmis New York, the company that owns Hot 97, made this statement:

When fans realized tickets were not available at the box office, a small number of people created an unsafe environment, and for the safety of all guests, the New Jersey State Police were on scene to disperse the crowd. The gates were closed at that time. No further entry was permitted into the event. For ticket holders whose tickets were not scanned, refunds will be offered at the point of purchase.

And here’s a video compilation of what was happening, including the armored vehicle with the alarm and fellow concertgoers trying to wash tear gas out of a girl’s eyes.

We’ll certainly learn more about what happened in the next few days. But there are fights all the time at big rock shows, and I’ve never seen a police response anything like this. Tensions between police and young people of color in the New York area are already high after Eric Garner’s killing last year. This isn’t going to help anything.

Meanwhile, even with all the chaos going on outside, the show still went on as planned. Meek Mill served as de facto headliner, bringing surprise guests Future and Nicki Minaj to the stage. Kendrick Lamar, probably the biggest name on the bill, brought Schoolboy Q, Ab-Soul, SZA, and viral star Welvin Da Great with him. Fabolous’ set turned into a big New York nostalgia-fest, with Mase, Lil Kim, Mobb Deep, Method Man, Redman, Raekwon, the Lox, Busta Rhymes, Fat Joe, Remy Ma, and others. Big Sean, Ty Dolla $ign, Trey Songz, Chris Brown, Fetty Wap, and others also performed. The whole show streamed live on Tidal, and you can see some videos over at Miss Info.