A stampede broke out at Barclays Center in Brooklyn, New York, just after midnight Sunday after a false report of an active shooting situation, New York police said.
A crowd was leaving the arena after a boxing match when a loud noise was heard, spooking the crowd and causing many to start running in fear of a shooter, police said in a statement.
About 10 people were injured and taken to hospitals, where they were stable, the statement said. All of the injuries were minor, police said.
Police determined that no shots had been fired in the area, and it remained unclear what caused the loud noise.
Tennis star Naomi Osaka, who was at the event, tweeted that she was "petrified."
"I was just in the Barclays center and suddenly I heard shouting and saw people running, then we were being yelled at that there was an active shooter and we had to huddle in a room and close the doors, I was so ... petrified man," she wrote.
She followed up saying she hoped everyone made it out safely.
About 19,000 people, including Osaka and Madonna, were in attendance Saturday night to watch the boxing match between undefeated lightweight champion Gervonta Davis and Rolando Romero, according to The Washington Post. It's unclear whether Madonna was present during the stampede.
Videos posted on Twitter showed shoes and hats left behind as people scrambled to flee.
The incident comes just days after a shooter in Uvalde, Texas, killed 19 children and two elementary school teachers and just weeks after a shooter in Buffalo, New York, killed 10 Black people in a supermarket.