Fourteen children were injured and their teacher killed as a school trip to Berlin ‘ended in a nightmare’ – a car was driven into the group.
A 29-year-old man suspected of being the driver, who has dual German-Armenian nationality, has been arrested, German police told Sky News.
Iris Spranger, the city’s home affairs minister, suggested the motorist may have mental health issues.
She said: “The latest evidence suggests this is a case of a mentally ill person going wild.”
Berlin police spokesman Martin Dams said earlier it was unclear whether the incident was an accident or whether the driver had intentionally rammed into the crowd.
The man was driving a small Renault car, Bild reported.
According to witnesses, he first fled and was arrested and handed over to the police, he added.
The children are from the small town of Bad Arolsen in the central German state of Hesse and are believed to be in grade 10, which means they are 16 and 17 years old. Their teacher died at the scene.
German Chancellor Olaf Scholz said the “horrific act” on a busy street had affected him deeply and he hopes those caught up in the crash will recover quickly.
He tweeted: “The journey of a school class from Hesse to Berlin ends in a nightmare. We are thinking of the relatives of the dead and injured, including many children. I wish them all a speedy recovery.”
The fire department said earlier that a dozen people were injured and six were in life-threatening condition.
An apparent confession letter was found in the car. German newspaper Bild quoted an investigator as saying, “(It was) by no means an accident – someone running amok, an icy killer.”
But officials denied the existence of a confessional letter, saying instead that posters about Turkey had apparently been discovered in the vehicle. Turkey has strained relations with Armenia.
Footage from the scene showed the silver car crashed into a department store window.
Blankets covered what appeared to be a body in a cordoned off area guarded by police.
Numerous paramedics and EMTs were at the scene.
Reporting from the scene, Sky News Europe correspondent Siobhan Robbins said the car drove down the street, then hit a group of people, returned to the road, came up the kerb again before swerving crush in a store.
It took place around 10.30am on Rankestrasse, near Breitscheidplatz in the main shopping district, scene of the 2016 Christmas market attack in which 11 people were killed.
It is also near the war-torn Kaiser Wilhelm Memorial Church, one of the city‘s best-known landmarks.
Actor John Barrowman, who was at the scene with husband Scott Gill, told Sky News he saw “a dead person in the middle of the road, covered”.
“The person came to the sidewalk near the Levi’s store and the bank, then drove into the street, hit the person and killed them in the street, then came back to the sidewalk, went down the sidewalk, walked through the cafe and then into the store front,” he said.
“How awful that this morning these people got up to have a normal day, they were doing their daily business. I mean, we were running errands, but if you think if we would have walked out of that store a minute longer early. ..”
He said: “We’re no experts, but it seems intentional – besides, the car went onto the pavement.”
“There were broken chairs and tables on the pavement – just a trail of destruction,” said Mr Gill, a British architect.
“You could see the car had zigzagged on and off the curb on the way down.”
“For the first 10-20 minutes it was just pure chaos,” he added. “We went through it without really realizing what was going on.”
“We’re pretty shocked,” Barrowman added, fighting back tears.
“To see people hurt, people who were just innocent and the senseless destruction of whoever caused this.
“Whoever did this is a horrible, horrible person…it’s just a vicious thing to do.”
“We believe we witnessed a terrorist attack here in Berlin,” he tweeted earlier.
“We saw a car that went down the road and ended up in a storefront covering three city blocks. It’s pretty horrifying.”
“There are police behind us, there are other police cars coming. There are helicopters coming. It’s bad. It’s serious,” he continued in video messages. posted on social media.
“There are hundreds of emergency services that are in the area, blocking off block after block. The cordon keeps growing.”