Nine people were arrested at the Kentucky State Fair, which closed Saturday night after suspicious activity was reported to law enforcement, authorities said.

Kentucky State Police said in a statement on Twitter that the fair began a “soft close” at about 10 p.m. Saturday to ensure the safety of attendees. Police said there were no reported injuries.

The initial investigation shows that a group of people “caused panic with noise-making devices, leading fair goers to believe shots” had been fired, police said Sunday in a news release. Investigators have found no physical evidence that a weapon was fired, but the investigation is ongoing, police said.

Three adults and six minors were charged with offenses including disorderly conduct, menacing, possession of stolen property and possession of a handgun, police said.

The fair resumed normal operations on Sunday, officials said.

The Kentucky State Fair, which began Thursday, is an annual multiday event held at the Kentucky Exposition Center in Louisville.