The two wounded people had only superficial injuries and were discharged from the Sahlgrenska hospital at around 3pm, according to a hospital spokesman. Several cars were destroyed in the blast, and there has been some damage to nearby buildings.
"It is likely that one car was blown up, and other cars around started to burn in conjunction with this," said police incident commander Niklas Eriksson.
It is so far unknown if any of the cars were being driven at the time of the explosion. It is also not clear who owns the cars.
Eriksson said that he did not know of any threats being received in connection with the incident.
Another car was blown up with a hand grenade in the Gothenburg suburb of Hisingen on Tuesday. It is so far unknown whether Wednesday's attack used a hand grenade.
"The technicians will make their judgment," said Eriksson.
"We are working on interviews with witnesses to try to get more information," he said. Police say they have so far not identified any suspects.
Christopher Hadward witnessed the explosion:
“I heard a bang and at first I didn’t understand at all what was going on, then I saw the black smoke,” he said, according to Göteborgs-Posten.
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