Berlin: A man smashed a vehicle into busy cafe and restaurant terraces in Germany on Saturday killing at least three people before shooting himself dead in front of horrified diners.

"The driver shot himself," a police spokeswoman said, adding that around 30 people were injured in the incident.

Images of the scene showed broken and upturned tables and chairs strewn across the pavement outside eateries in the centre of the picturesque medieval city of Muenster as media reports said the driver was a German national in his late 40s with a history of mental health problems and no known links to "terrorism".

Public broadcaster ZDF said the man had recently attempted suicide. Police in the northwestern university city did not immediately confirm the reports.

At least 20 people were injured, six of them seriously.

"There was a bang and then screaming. The police arrived and got everyone out of here," an employee of one the cafes hardest hit by the rampage told rolling news channels N24 and NTV.

"There were a lot of people screaming. I'm angry - it's cowardly to do something like this."

Armed police were deployed and officers urged residents to avoid the city centre to allow investigators to get to work amid initial fears the country had suffered another extremist assault.

Images broadcast by German television showed several police and firefighting vehicles clustered around a street in the centre of the picturesque medieval city of 300,000 people.

Armed police were deployed and officers urged residents to avoid the city centre to allow investigators to get to work.

Germany has experienced a number of terror attacks in recent years, including through the deadly use of vehicles.

In December 19, 2016, Tunisian national Anis Amri, 24, hijacked a truck and slammed it into a crowd of people at a Christmas market in Berlin, killing 12 people and injuring 48.

Amri was shot dead by Italian police in Milan four days later after travelling through several European countries. Daesh terrorist group claimed responsibility for that attack.

Daesh also claimed several similar attacks in Europe, including a rampage along Barcelona’s Las Ramblas boulevard in August 2017 that killed 14 and left more than 100 injured.

The deadliest such incident in recent years was in the French resort city of Nice in 2016, where a man rammed a truck into a crowd on France’s national July 14 holiday, killing 86 people.