Copenhagen shooting: Three killed, several injured, with suspect aged 22 arrested
The young man, who witnesses alleged was armed with a large rifle, was arrested peacefully shortly after police arrived at the large Fields shopping mall, located between the city centre and Copenhagen airport.
"There are three dead and several injured, three of them in critical condition," Copenhagen police chief inspector Soren Thomassen told a news conference.
The motives of the suspect, described by police as a 22-year-old "ethnic Dane", remain unclear.
He was known to the police "but only peripherally", Thomassen said.
"He's not someone we particularly know."
The three dead were a man in his forties and two young people whose ages were not specified.
On social networks people had been speculating about a racist motive, or some other motive, the head of the investigation said, "but I cannot say that we have anything which supports that at this moment".
Police however confirmed they were investigating videos posted online which claimed to show the suspect with weapons and pointing a gun at his head.
Earlier Thomassen said police "can't exclude that it's terror" but they believed the alleged shooter acted alone.
Images from the scene showed parents carrying their children as they fled the building and ambulance personnel taking people away on stretchers.
'We ran for our lives'
The shooting occurred around 5:30pm, causing panic in the mall.
Many visitors were there for a concert with British singer Harry Styles at the nearby Royal Arena, which was cancelled.
"My daughters were supposed to go see Harry Styles. They called me to say someone was shooting. They were in a restaurant when it happened," Hans Christian Stolz, a 53-year-old Swede who came to pick up his children, told AFP.
"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.
"My team and I pray for everyone involved in the Copenhagen shopping mall shooting. I am shocked," Styles said in a Snapchat post.
The attack occurred two days after this year's Tour de France cycling competition started from Copenhagen, and the Tour organisers released a statement expressing their sympathy.
"The entire caravan of the Tour de France sends its sincerest condolences to the victims and their families," it said.
Witnesses quoted by the Danish media alleged the suspect had tried to trick people by saying his weapon was a fake one, to get them to approach.
"He was sufficiently psychopathic to go and hunt people, but he wasn't running," one witness told DR state television.
Other eyewitnesses told Danish media they had seen more than 100 people rush towards the mall's exit as the first shots were fired.
"We could see that many people suddenly ran towards the exit and then we heard a bang," Thea Schmidt, who was in the mall at the time of the attack told broadcaster TV2.
"Then we ran out of Field's too."
'We heard gunshots'
Police had urged people in the building to wait inside for their arrival, calling on others to keep away from the area.
Police also asked witnesses to get in touch with them and called on those who had been visiting the shopping mall to contact loved ones to reassure them.
"All of a sudden we heard gunshots, I heard 10 shots, and we ran as far as we could to take refuge in the toilet," Isabella told public broadcaster DR.
She said she had hidden in the mall for two hours.
Other witnesses described the gunman as a man around 1.8 metres (five feet nine inches) tall carrying a hunting rifle.
At around 7:30pm (1730 GMT), roads around the mall were blocked, the subway was closed and a helicopter was flying above, said an AFP correspondent at the scene.
Heavily armed police kept onlookers back and prevented locals from returning to their homes.
Prime Minister Mette Frederiksen said Denmark had been hit by "a cruel attack" at a mall where families were shopping or eating out.
The shooting comes just over a week after a gunman opened fire near a gay bar in Oslo in neighbouring Norway, killing two people and wounding 21 others.
In February of 2015, two people were killed and five injured in Copenhagen in a series of Islamist-motivated shootings.