Many cars have been set on fire in Sweden overnight, which according to the police may be a co-ordinated criminal action.
Up to 80 vehicles were badly damaged by gangs of black-clad youths, beginning at about 21:00 local time (19:00 GMT).
Most of the damage took place in the western city of Gothenburg, but incidents were also reported in cities up to 100km (60 miles) away.
Prime Minister Stefan Lofven said: "It looks very coordinated, almost like a military operation."
Cars were also damaged in Trollhattan to the north of Gothenburg, and Falkenberg to the south.
According to the Swedish media, the masked young people broke car windows before pouring flammable liquids inside.
The police said that they had identified some young people who were in the area at the time and spoken to their parents - but officers could not say which, if any, were involved in the fires.
Speaking to Swedish Radio, Prime Minister Lofven addressed the attackers, simply asking: "What the hell are you doing?"
There is no clear motive for the widespread destruction.