DALLAS (AP) — One person was killed, and 11 others were injured during a shooting at an outdoor concert in Dallas, police said.

At about 12:13 a.m. on Sunday, officers responded to a field in southeast Dallas where a concert was being held, police said in a statement.

Police say a preliminary investigation has found that during the concert, one person fired a gun into the air, then another unknown individual fired a gun in the crowd’s direction.

Near the concert stage, police found 26-year-old Kealon Dejuane Gilmore lying on the ground with a gunshot wound to the head. Gilmore died at the scene.

Police say that 11 other individuals were shot during the concert. All the people who were hurt were taken to hospitals either by ambulance or by private vehicles. One person was in critical condition, and the others were in stable condition. Three of the people hurt are juveniles, police said.

Lulu Smith, who attended the concert with her daughter, told WFAA-TV that it was part of a trail ride event in which people drove their all-terrain vehicles, sat in the bed of trucks and paraded through the property before finishing up for a concert at the main stage.

Witnesses told the TV station the shooting happened after a fight broke out.

“Everybody was running,” Smith said. “It was so jam-packed right here, you couldn’t get in or out. When I got to my car, somebody was shooting. I rolled down my window, and I heard (shots).”

No arrests have been made as police continue to investigate what prompted the shooting.

In a statement, Dallas Mayor Eric Johnson called the shooting “horrific and unacceptable.”

“Public safety remains our top priority, and I will be conferring with Police Chief Eddie Garcia to see what more can be done to stop this kind of violence in our city,” Johnson said.

Saturday night’s shooting happened two weeks after 10 people were shot on March 19 during a spring break party at a Dallas event venue.