A German-Armenian man drove into a crowd in a busy shopping district in Berlin on Wednesday, mowing down a group of teenagers and killing their teacher before crashing through a shop window.

The incident happened at around 10:30 am (0830 GMT) just across from Breitscheidplatz, where an Islamic State group sympathiser deliberately ploughed a truck into a Christmas market in 2016, killing 12.

At least a dozen people were injured including six who remain in a life-threatening condition, emergency services said.

Police said it was not clear whether the crash was intentional
Police said it was not clear whether the crash was intentional AFP / Odd ANDERSEN

It was not clear whether the crash was intentional. The driver, 29, was being questioned, police told AFP.

The silver Renault Clio with a Berlin licence plate first mounted the sidewalk on the corner of Tauentzienstrasse and Rankestrasse, hitting the group of secondary school students on a class trip, before returning to the road.

It then rammed into the shop front on Marburger Strasse about 150 to 200 metres (165 to 220 yards) away.

The car ended up smashing into a shop front
The car ended up smashing into a shop front AFP / Odd ANDERSEN

A female teacher with the group from a school in Bad Arolsen, a small town in the central German state of Hesse, was killed. A male teacher was seriously injured, the Hesse state government said in a statement.

The driver was briefly detained by passers-by before being handed over to police after the car smashed through the shop front, according to police.

Eight people were taken to hospital -- five in a life-threatening condition, the fire service said
Eight people were taken to hospital -- five in a life-threatening condition, the fire service said AFP / John MACDOUGALL

Berlin police chief Barbara Slowik said the driver was in hospital and "at this time, we do not have conclusive evidence of a political act".

Later Wednesday, however, Berlin interior minister Iris Spranger said on Twitter that "according to latest information" the attack seemed to have been "committed by someone suffering from psychological problems".

Spranger earlier denied media reports a letter of confession was found in the car, but said there were "posters with remarks about Turkey".

The car ended up smashing into a shop front
The car ended up smashing into a shop front AFP / Odd ANDERSEN

However, security sources told AFP the car did not belong to the driver and cautioned that the contents of the vehicle may not be his.

Frank Vittchen, a witness at the scene, told AFP he was sitting at a fountain nearby when he "heard a big crash and then also saw a person fly through the air".

The vehicle drove "at high speed onto the pavement and didn't brake", he said, with its windows shattering from the impact.

"It all happened so fast," he said.

Another witness who would only be named as F. Kacan said the driver had ploughed his car into the perfume store, and "then he suddenly took off running on the street and we were able to stop him".

The German government is "very concerned and shocked" by the "terrible incident in Berlin", said a spokeswoman, adding that their thoughts were with the victims and their loved ones.

Germany has been on high alert for car ramming attacks since the deadly 2016 Christmas market assault, with most carried out by people who were found to have psychological issues.

In December 2020, a German man ploughed his car through a pedestrian shopping street in the southwestern city of Trier, killing four adults and a baby.

Earlier the same year, a German man rammed his car through a carnival procession in the central town of Volkmarsen, injuring dozens of bystanders, including children. He was sentenced to life in jail last year.

In January 2019, another German man injured eight people when he drove into crowds on New Year's Eve in the western cities of Bottrop and Essen. He was later taken into psychiatric care.

During the football World Cup in Germany in 2006, a German man rammed his car into crowds gathered to watch a match at the Brandenburg Gate in Berlin, injuring some 20 people. The driver was later committed to a psychiatric hospital.