A man arrested on suspicion of killing three people and wounding several others during a shooting at a shopping mall in Copenhagen was known to psychiatric professionals, Danish police said Monday.

The shooting unfolded on Sunday at multiple locations inside Field’s, a shopping center in the Danish capital. Social media footage showed people running through the mall and heavily armed law enforcement officers on the scene.

At a press conference on Monday morning, Copenhagen’s Head of Police Soren Thomassen said two 17-year-old Danish citizens, one male and one female and a 47-year-old Russian national had been killed in the gunfire.

Two other Danes and two Swedish nationals had received gunshot wounds and were in hospital in critical but stable conditions, while several others sustained minor injuries while leaving the mall, Thomassen said.

A 22-year-old Danish man was arrested in connection with the shooting and is currently the only suspect. Thomassen said there is no indication the suspect was acting with others but an investigation was ongoing.

Earlier, the police had said they detained the suspect 13 minutes after receiving the first emergency call, and that he was “carrying a rifle and ammunition” at the time of his arrest.

At the press conference on Monday, Thomassen said there is no indication the attack was an “act of terror” nor motivated by gender, and police believe the victims were chosen at random. The suspect was “known to people in the psychiatric field,” he said.

The suspect will be charged with manslaughter, Thomassen said.

‘Run, run, run, they’re still shooting in there’

Eyewitness Joachim Olsen, a former Danish politician and athlete, told CNN that he was on his way to a gym inside Field’s when he saw large groups of people exiting the mall.

“It looked like something, I’m sorry to say, like something you would see from a school shooting in the US, people coming out with their hands above their heads,” Olsen said.

“You have people running out, looking for friends and calling friends and family members who were inside, some speaking to friends who were inside,” he said. “Old people with their arms around the necks of people carrying them out, their feet just being dragged across the floor.”

Outside the mall, Olsen spoke to a man who spoke to an off-duty paramedic whose arms “were covered in blood up to his elbows.”

“He wanted to go back in but the police wouldn’t let him,” Olsen said.

According to Olsen, security tried to get the crowds to move away from the mall.

“At one point we were rushed away. The police came and said ‘Run, run, run, they’re still shooting in there.'”

A spokesman for Rigshospitalet, Denmark’s largest hospital, told CNN that the hospital had taken in several victims and had called in extra staff to deal with the emergency.

A phone line for victims has been opened and police said they have set up a central location where eyewitnesses can get support and report their experiences to law enforcement officials.

Danish police said Sunday they had evacuated thousands from the Royal Arena venue next to the mall. The arena had been scheduled to hold a Harry Styles concert, but this was canceled following the shooting.

In a statement Sunday night, Danish Prime Minister Mette Frederiksen sent sympathy to the wounded, their relatives and the bereaved, as well as “all the Danes who were close to these frightening events.”

“We have all been brutally ripped from the bright summer that had just begun. It is incomprehensible. Heartbreaking. Meaningless. Our beautiful and usually so safe capital was changed in a split second,” Frederiksen said.

In a statement, Denmark’s Royal House said, “Our thoughts and deepest sympathy are with the victims, their relatives and all those affected by the tragedy.”
The President of the European Parliament, Roberta Metsola, also expressed solidarity with the people of Denmark.

“Thinking of everyone in #Copenhagen tonight after horrific reports of several people killed in a shooting in a shopping mall. We are with you Denmark,” she tweeted.

Gun violence is relatively rare in Denmark. Copenhagen’s last major shooting incident was in 2015, when a gunman attacked a free speech forum featuring controversial cartoonist Lars Vilks, killing one man and wounding three others.