A gunman opened fire near the food court of a crowded Columbia, South Carolina shopping mall Saturday, shooting 10 and leaving two others injured when they were trampled in the chaos.

There were no fatalities in the shooting and nine of the patients had been treated and released, according to local outlet WLTX.

Three “persons of interest” were detained by police after they were seen with firearms in the mall, said Columbia Police Chief W. H. “Skip” Holbrook at a press conference. At least one of the three fired a weapon, but he said police were still sorting out exactly how the gunplay unfolded. None had yet been arrested and it was not yet clear how many shots had been fired.

“We don’t believe this was random. I think that’s very important in situations like this,” Holbrook said. “We believe the individuals that were armed knew each other and there was some kind of conflict that occurred that resulted in gunfire.

“This was not a situation where we had some random person show up at a mall to discharge a firearm and injure people,” Holbrook said.

Eight people were taken to area hospitals and two were in critical condition, Holbrook said. The oldest person shot was 73, the youngest was 15.

Cindy Paris Rectenwald and her daughter Rachel were in the food court at the Columbiana Centre, about 10 miles northwest of the state capitol, when the shooter began to fire about 2 p.m., they told The State newspaper. They said it sounded like a rapid series of pops, very quick with no sounds of reloading.

They thought it was rain hitting the glass roof until they saw people running toward them.

People were “screaming and yelling” as they ran for the exit doors in the food court, said Rectenwald, who with her daughter jumped up and joined the fleeing crowd.

J. Canty, a security guard, told The State it was still an active situation late in the afternoon, as law enforcement officials tried to clear the mail out after evacuating most of the shoppers.

The department tweeted to store employees who were told the shelter in place that they should contact the police for an escort out.

“Today’s isolated, senseless act of violence is extremely upsetting and our thoughts are with everyone impacted. We are grateful for the quick response and continued support of our security team and our partners in law enforcement,” the Columbiana Centre said in a statement.