COPENHAGEN — A gunman has killed three people and wounded others, three of them critically, at one of Denmark's biggest shopping malls, police say.

The 22-year-old man, described as "an ethnic Dane", was arrested and charged with the attack which sparked panic at Field's mall in south Copenhagen.

Police chief Soeren Thomassen said the motive was unclear and he could not rule out an "act of terrorism".

The suspect will face questioning by a judge on Monday.

Prime Minister Mette Frederiksen said Denmark had suffered a cruel attack.

She said she wanted to encourage Danes to stand together and support each other in this difficult time.

"Our beautiful and usually so safe capital was changed in a split second," she said.

The deadly shopping mall attack took place as Denmark celebrated hosting the first three stages of the Tour de France for the first time.

The suspect had a rifle and ammunition when he was arrested, police said.

They have no indication that other attackers were involved and urged shop owners to preserve any video surveillance footage they might have.

Field's has more than 140 shops and restaurants. The multi-story mall is on the outskirts of Copenhagen, just across from a subway line that connects to the city center.

Eyewitnesses spoke of panic among shoppers as gunfire rang out.

One of them, named Isabelle, told Danish media: "Suddenly we hear shots. I think I hear ten shots and then we run through the mall and end up in a toilet, where we huddle together in this tiny toilet, where we are around 11 people.

"It's really hot and we wait and we are really scared. It's been a terrible experience."

A concert by British singer Harry Styles at a venue less than a mile from the scene was canceled.

Crowds had already gathered inside the venue when the show's cancellation was announced. Fans - many in their teens - were escorted by police to underground stations where parents picked them up, Danish media report.

"My daughters were supposed to go see Harry Styles," Hans Christian Stolz, a 53-year-old Swede who came to pick up his children, told AFP. "They called me to say someone was shooting. They were in a restaurant when it happened."

"We thought at first people were running because they had seen Harry Styles, then we understood that it was people in panic... We ran for our lives," his daughter Cassandra said.

Writing on Snapchat, Styles said: "My team and I pray for everyone involved in the Copenhagen shopping mall shooting. I am shocked. Love H."

Shortly after the shooting, the Danish royal family announced that a reception due to be hosted by Crown Prince Frederik to celebrate hosting the Tour de France's first three stages had been canceled.

Several neighboring leaders expressed horror at the shooting and offered condolences to the families of those impacted.

Finnish Prime Minister Sanna Marin condemned what she called a "shocking act of violence" and Norwegian leader Jonas Gahr Store said his "thoughts go to the victims and their relatives and to the relief crews who are currently working to save lives".

Denmark last saw a major terror event in 2015, when two people were killed and six police officers were injured during an attack on a cultural center and a synagogue in Copenhagen.

The gunman was later killed in a shootout with police.

The country has some of the strictest gun laws in Europe, with licences to own firearms usually only available for hunting or sport shooting following background checks - and with an almost total ban on automatic weapons. Carrying a firearm in public is strictly prohibited. — BBC