The fire was started in a garage in Gränby, in the north of the city, shortly before 2am on Monday morning. Firefighters extinguished the flames around two hours later.
“It was two cars that were burning, but the garage contained around 100 cars which have been damaged to a greater or lesser extent by the heat. The fire was contained in the garage the whole time,” Bosse Eriksson from Uppsala's emergency services told the TT newswire.
Eriksson added that the fire was “probably” caused deliberately, but police have not yet made any arrests.
It comes after a spate of similar attacks last week, mostly across Gothenburg and the west of the country with around 80 cars set on fire in the region. Police said those attacks may have been coordinated.
On Saturday night, there were eight new car burnings across western Sweden, Göteborgs Posten reported, with between one and three vehicles affected in each incident. Police said they suspected the fires to have been started deliberately, but had not identified the suspects.
A police press officer said that they didn't believe Saturday's car burnings were connected to each other or to the arson incidents last week. Instead, she told the newspaper they were likely isolated incidents which typically occur shortly before the start of the school year.