At least nine people have been charged for allegedly organizing a massive—and illegal—Halloween party in Brooklyn.

According to the New York City Sheriff's Office, deputies determined more than 387 people attended the event hosted at a warehouse near East Williamsburg. Authorities, who busted the party at around 1 a.m. Saturday, say the rager's size violated the city and state's coronavirus emergency orders prohibiting large gatherings. Photos taken at the event showed the space packed with party-goers, many of whom were seen without masks. 

According to NBC News, deputies also found three bars inside the warehouse and a DJ booth. The party's alleged organizers were charged with multiple misdemeanors and health violations. Several attendees were also charged with disorderly conduct and resisting arrest.

News of the bust comes as NYC officials reported a spike in COVID-19 cases. The city tallied more than 3,600 new infections this week and announced its positivity rate hit 2.7 percent, with the seven-day average at 1.92 percent. Mayor Bill de Blasio expressed concern over the rising case numbers, and urged New Yorkers to continue to take precautions. 

"The growth is what worries me. And we cannot allow that number to keep growing. We’re really going to have to double down,” the mayor said this week, as reported by Politico. "This is a dangerous time, and we have to take it really, really seriously ... People really should not travel for the holidays unless it’s absolutely necessary, because unfortunately just about everywhere else is doing worse at fighting the coronavirus,” he said. “If you go some place else, the chance of bringing it back with you is high."