
Ms Adomeit went on to say there was no indication the perpetrator had any political motives for the attack.
Saturday's attack in Muenster came a year to the day of a truck attack in Stockholm in which a suspected Islamist militant sympathizer links killed five people.
Several of the more than 20 victims injured in Saturday's van attack in the western German city of Muenster remained in critical condition, a local police spokeswoman.
But authorities could not yet determine the exact motive for the attack.
As per witnesses, the people were seen running all over moments after the attack.
More news: Danny Welbeck Bags A Brace As Arsenal Edge Out SouthamptonMuenster Police President Hajo Kuhlisch says "we are now focusing our investigations on getting a comprehensive picture of the perpetrator's behavior in the weeks (before the crash) to find out his motivation for this terrible act".
The driver was a German citizen, said Herbert Reul, state minister for internal affairs in North Rhine-Westphalia. "Investigations are being conducted at full speed and covering all possible directions".
Two people were killed when the driver mowed down dozens before killing himself.
.Arlt said the old city remains closed, and police have asked people to avoid the city center.
"This was a frightful and sad day for the people of Muenster, all of Germany", said Armin Laschet, the governor of the German state where the attack happened.
More news: Apple Could Hit $1 Trillion Valuation With Curved iPhoneIn a joint statement with police, prosecutor Martin Botzenhardt wrote Sunday that, "as of now, we don't have any leads regarding a possible background for the deed". "Everything possible is being done to investigate the act and support the victims and their families".
Police spokesman Bode also said a suspicious object had been found in the vehicle which was being examined.
On the other hand, the Associated Press reported that according to a police spokesperson, media reports on perpetrator having psychological issues too have not been confirmed.
A search of the man's Muenster apartment late Saturday turned up more fireworks and a deactivated AK47 assault rifle.
Muenster is a popular tourist destination with 300,000 inhabitants, known for its medieval old town, which was rebuilt after the massive destruction during World War II.
More news: Aussie boxer gifted first medal of Games without a punch thrownIt happened as people were eating outside a restaurant in the city's historic centre just before 3.30pm on Saturday afternoon. Police quickly evacuated the area and ambulances, firefighters and helicopters rushed to the scene to aid those who were injured.