At 10.30 pm on Thursday evening, alarms were received almost simultaneously about fires in five places in Trollhättan.
The fires ravaged, among other things, parking garages and a terraced house that is to be uninhabited, writes TT.
At the same time, up to 30 cars were on fire, reports P4 Väst.
The rescue service went into staff mode with assistance from colleagues in Uddevalla.
During the night, the public is urged to "close doors, windows and ventilation" due to the development of smoke.
At 05.30 on Friday, the rescue service announced that they had completed almost all operations.
The fires are being investigated as arson and vandalism.
At seven o'clock on Friday morning, the police had not made any arrests.
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During the night, they burned, among other things, in a parking garage in central Trollhättan.
Several cars were also set on fire.
Photo: Robert Betzehag