German prosecutors have no indication why a 48-year-old man drove a van into a crowd of people in the western city of Munster, killing two and injuring 20 before shooting himself dead inside the van.
"As of now, we don't have any leads regarding a possible background for the deed," prosecutor Martin Botzenhardt wrote in a joint statement with police.
"The investigations are being led under high pressure in all possible directions."
Authorities have identified the two fatalities of Saturday's crash as a 51-year-old woman from Lueneburg County and a 65-year-old man from Broken County.
The city's Roman Catholic bishop, Felix Glenn, invited all of Munster's citizens to a joint Catholic-Lutheran memorial service at the famous Paulus Cathedral on Sunday night.
Local media have identified the perpetrator as a German industrial designer living in Munster who had been suffering from psychological problems, but police would not confirm the details.
All three bodies were taken from the scene in front of the well-known Kiepenkerl pub early on Sunday night.
The silver-grey van was hauled away hours later after explosives experts had thoroughly checked it.
"The van is not at the crime scene any more, all kinds of objects have also been removed, waste of course, as well as evidence that we've found on the ground," police spokeswoman Susanne Dirkorte said.
Inside the van, police found illegal firecrackers disguised as a fake bomb, a fake pistol and the gun the perpetrator used to kill himself.
Inside the man's apartment, which was near the crash scene and raided late on Saturday, police found more firecrackers and a "no longer usable AK-47 machine gun".
Police said some of the 20 injured people were in life-threatening condition, but did not release further details.
The local daily Muenstersche Zeitung reported that the perpetrator had vaguely announced his suicide plans a week ago in an email to friends, and that he was known to the authorities for previous violence and drug violations.
The city was buzzing on one of the first warm spring days of the year and people were sitting outside the Kiepenkerl when he drove into the bar's tables with such force that the van only came to a stop when it hit the wall of the pub.
Police quickly evacuated the area and ambulances, firefighters and helicopters rushed to the scene to aid the injured.
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