The first blast occurred shortly before 11pm on Sunday near a police car which was out on patrol in the city’s Hvitfeldtsplatsen neighbourhood.
Police suspected that someone may have thrown a hand grenade at the vehicle.
“Colleagues in the car think so, judging from the strength of the explosion and now we’re looking for fragments in the area,” said Johan Ljung of the Gothenburg police to the TT news agency.
Shortly after midnight, another blast occurred in a public toilet near Kungsparken, close to the Stora teatern theatre.
The explosion was thought to be of roughly the same strength as the evening’s first blast.
“The blast was of equal power, so it seems as if both incidents are related. Which makes one think it could have been a coincidence that a police car was in the area when the explosion occurred. It can also be a diversionary tactic for something else taking place,” said Per Mattson of the Gothenburg police to TT.
Police still don’t know what sort of explosive material was used in either blast and both areas remained blocked off through the night while police conducted investigations.
Following the first explosion, police said they believed two assailants between 25 and 30-years-old were involved.
No one was injured in either explosion.