One person was fatally shot and at least 22 others were injured in gunfire that broke out during a Juneteenth celebration in Illinois early on Sunday morning, authorities said.

The mass shooting happened at around 12:30 a.m. in Willowbrook, a suburban village about 20 miles west of Chicago, where a large crowd of young people had gathered for a party in a parking lot near Route 83, a major state highway. Police patrolling the area were called away around that time to respond to another report alleging a fight had happened nearby. They returned to the gathering after hearing gunshots, the DuPage County Sheriff's Office said in a news release.

An unknown number of suspects fired multiple rounds from multiple weapons into the crowd, according to the sheriff. Earlier Sunday, witnesses told CBS Chicago that they recalled hearing between 20 or 30 gunshots fired during the event, which was attended by more than 200 teenagers and young adults. Witnesses and law enforcement said the Juneteenth celebration was peaceful until the shooting started.

"I got kids to come back home to. I'm not used to this," one woman who witnessed the shooting said to CBS Chicago. "I wasn't expecting it, but you just never know. Anything can happen anywhere."

Another witness recalled hearing numerous gunshots.

"Anything could've happened. It was a lot of people out, we were all having a good time but, you know," he told the news station.

In addition to the attendees who were shot, several other victims were injured while trying to flee the scene of the shooting, the sheriff's office said. Victims are being treated at different hospitals in the area. Their conditions were unknown at the time of the sheriff's news release.

Authorities have not identified a suspect or possible motive for the shooting, and details about the individuals who were harmed in the attack have not been made public. An investigation is underway at the sheriff's office, with detectives interviewing victims and witnesses, and reviewing camera footage from the area and witnesses' cell phones. The area and businesses surrounding the site of the shooting will be closed until further notice, the office said.

In:
• Illinois
• Shooting
• Juneteenth
• Mass Shooting
• Crime