The fire in the pizzeria is said to have started with a couple of waves of fire and then spread to the facade and roof.
Emergency services and police are called to the scene and the fire can be extinguished.
Police cordon off the restaurant and prepare to begin a technical investigation as soon as the area has cooled down.
As there is reason to believe that the fire was arson, the police begin a preliminary investigation into arson.
No one should have been injured, but property of great value determines the classification.
Three arrested - suspected of arson
Later on Wednesday morning, three young men were arrested in another part of Uppsala, suspected of the arson.
At the moment, the police cannot answer whether there is a connection to the previous fires.