BROOKLYN (PIX11) — More than a dozen people were injured when a loud noise sparked panic at the Barclays Center early on Sunday after a boxing match, officials said.

The crowd mistook a loud noise outside the arena for a gun being shot, police said. The crowd of fans there to watch Gervonta Davis and Rolando Romero fight ran when they heard the sound. People pushed and shoved each other. Some people were trampled.

Many fans attempting to depart Barclays Center ran back in toward the arena floor, some even leaping up into the ring in panic. Security held some fans in one area for a time until it was deemed safe to leave.

Police said no actual shots were fired.

In all, 18 people were injured, an FDNY spokesperson said. Nine of the victims needed to be taken to area hospitals for treatment.

Tennis star Naomi Osaka was among the frantic fans at Barclays Center. She took to Twitter and posted that she was “petrified.”

“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 (expletive) petrified man,” the four-time grand slam champion tweeted. A short time later, she added: “I really hope everyone made it out safely, since I’m tweeting this we made it out ok.”