One person has been killed and at least a dozen more injured after a car drove into a crowd on a busy Berlin street.
Emergency officials say it is unclear whether the incident, which happened at around 10:30 local time (08:30 GMT), was intentional or an accident.
A police spokesperson told reporters that the driver, a 29-year-old man, was arrested at the scene.
The incident took place in the heart of western Berlin, on one of its busiest shopping streets.
"There are seriously injured people among the more than a dozen injured," police spokesperson Thilo Cablitz said.
Police added that the driver, who has dual German and Armenian citizenship and lives in Berlin, had initially been apprehended by passers-by.
Reports say the vehicle veered off the street and mounted the pavement before crashing into a shop front.
Images from the scene show a silver Renault Clio that had crashed through a display window in a cosmetics shop. There are also pictures of what appears to be a body, covered in blankets, in the middle of the road.
Around 130 emergency workers are at the scene according to the Berlin police service.
Berlin's Mayor Franziska Giffey wrote on Twitter that she has been "deeply affected by this incident" and told residents that "police are working flat out to clarify the matter".
"I will get an idea of the situation on-site during the course of the day. I would like to thank the more than 130 emergency services for their quick response and care for those affected," she added.
The actor John Barrowman tweeted that he was nearby when the incident took place and in a video posted from the scene said the car had repeatedly mounted the footpath before crashing into the storefront.
"The police presence is unbelievable. They are clearing out the area," the actor said. "There are helicopters coming in now to airlift people."
Mr Barrowman later told the BBC the car careened through tables of people sitting outside having breakfast, before smashing into the storefront.
"It was just horrific", he said. "I saw somebody being resuscitated, I saw somebody being literally thrown onto a stretcher and put into an ambulance," he added.
The incident happened on the corner of the busy Rankestrasse and Tauentzienstrasse in western Berlin.
The area is opposite Breitscheidplatz, where 12 people were killed when a truck driver deliberately drove his lorry into a crowd of people at a Christmas market.
IS later claimed responsibility for the attack, which was carried out by an unsuccessful asylum seeker. The attacker was later shot dead by Italian police.