Seven people were shot, two fatally, at a high school graduation ceremony outside a theatre in the US city of Richmond, Virginia.
Hundreds of attendees fled in panic, wept and clutched their children as shots were fired at the end of the ceremony on Tuesday, 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, Richmond's interim police chief, Rick Edwards, said during a news conference at which he confirmed the two fatalities.
Five others were wounded in the incident 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 caused by the mayhem, according to police.
“As they heard the gunfire, it was obviously chaos," Mr Edwards said. "We had hundreds of people in Monroe Park, so people scattered. It was very chaotic at the scene.”
Mr 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,” Mr 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 taken to VCU Medical Centre where their conditions late on Tuesday ranged from serious to critical, a spokeswoman said.
Several handguns were recovered. Police initially said two suspects were detained, but Mr Edwards said later that they had determined that one of them was not involved.
Richmond Mayor Levar Stoney vowed to ensure that anyone responsible faced justice.
"This should not be happening anywhere,” he said.
Officers inside the theatre, where the graduation ceremony for Huguenot High School had been taking place, heard gunfire about 5.15pm and radioed to police stationed outside, who found several victims, Mr 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,” Mr 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.
“I don’t have any more words on this,” Mr Kamras said. “I’m just tired of seeing people get shot, our kids get shot. And I beg the entire community to stop, to just stop.”
As he heard the gunshots and then sirens, neighbour John Willard, 69, stepped on to the balcony of his 18th-floor apartment. Below, he saw students fleeing in their graduation outfits and parents hugging children.
“There was one poor woman in front of the apartment block next to ours who was wailing and crying,” Mr Willard said, adding that the scene left him deeply saddened.
Edythe Payne was helping her daughter sell flowers outside the theatre to students as they left the ceremony.
She told the Richmond Times-Dispatch that the shooting caused a panic on nearby Main Street, which was packed with people at the time.
“I felt bad because some elderly people were at the graduation and they got knocked down to the ground,” Ms Payne said.
The school district said a different graduation scheduled for later on Tuesday had been cancelled “out of an abundance of caution" and schools would be closed on Wednesday.
The mass shooting, the latest in a nation increasingly accustomed to them, again prompted calls for reform.
“The gun violence epidemic is a public health crisis that we must address,” US representive Jennifer McClellan, a Democrat whose district includes Richmond, said in a statement.
“We cannot continue to live in fear. We must address the root causes of gun violence and pass common-sense gun-safety policies that protect our communities.”
Republican Lt Gov Winsome Earle-Sears, an ardent gun-rights advocate, said in remarks to news outlets near the scene that the problem lay not with guns but with criminals.
“We have to figure out what’s going on in our communities,” she said.
