RICHMOND, Virginia (AP) — Seven people were shot, two fatally, when gunfire rang out Tuesday outside a downtown theatre in Richmond, Virginia, where a high school graduation ceremony had just ended, causing hundreds of attendees to flee in panic, weep and clutch their children, authorities and witnesses said.

A 19-year-old suspect tried to escape on foot but was arrested and will be charged with two counts of second-degree murder, Interim Richmond Police Chief Rick Edwards said during a nighttime news conference at which he confirmed the two fatalities.

Five others were wounded by the gunfire outside the state capital's city-owned Altria Theatre, which is across the street from a large, grassy park and in the middle of the Virginia Commonwealth University campus. At least 12 others were injured or treated for anxiety due to the mayhem, according to police.

"As they heard the gunfire, it was obviously chaos," Edwards said. "We had hundreds of people in Monroe Park, so people scattered. It was very chaotic at the scene."

Edwards said one of the people who was killed was an 18-year-old male student who had just graduated, while the other was a 36-year-old man who was there for the graduation. Their names were not released, but police believe the suspect, who was not immediately identified, knew at least one of the victims.

"This should have been a safe space. People should have felt safe at a graduation," Edwards said.

"It's just incredibly tragic that someone decided to bring a gun to this incident and rain terror on our community."

Six people were brought to VCU Medical Center and their conditions ranged from serious to critical late Tuesday, VCU Health System spokesperson Mary Kate Brogan said.

Multiple handguns were recovered. Police initially said two suspects were detained, but Edwards said later that they determined one of them was not involved.

Richmond Mayor Levar Stoney vowed to ensure anyone responsible faces justice.

"This should not be happening anywhere," Stoney said.

Officers inside the theatre, where the graduation ceremony for Huguenot High School had been taking place, heard gunfire around 5:15 pm and radioed to police stationed outside, who found multiple victims, Edwards said.

School board member Jonathan Young told Richmond TV station WWBT that graduates and other attendees were leaving the building when they heard about 20 gunshots in rapid succession.

"That prompted, as you would expect, hundreds of persons in an effort to flee the gunfire to return to the building," Young said.

"It materialised in a stampede," he said.

Two people were treated for falls; one juvenile was struck by a car and sustained injuries that were not life-threatening; and nine people were treated at the scene for minor injuries or anxiety, according to police spokeswoman Tracy Walker.

Richmond Public Schools Superintendent Jason Kamras said the new graduates were outside taking photos with families and friends when the shooting broke out.