Three of the injured people were taken to Mölndal hospital.
The collision occurred between a tram plying route five from Östra Sjukhuset to Länmandsgården. On approaching the Avenyn/Vasagatan crossing, it crashed into a tram plying route one from Tynnered to Östra Sjukhuset.
The route five tram crashed into the side of the other, forcing both off the rails.
The accident has caused traffic chaos in central Gothenburg as it is expected to take a significant amount of time to clear the carriages. Problems have been accentuated by summer road works in various parts of the city directing more traffic through the busy road junction at Avenyn/Vasagatan.
It remained unclear at midday on Thursday which driver was at fault and should have given way.
"We don't know who should have stopped, that will emerge. But the driver in our tram acted in a very professional manner," said a passenger to the local Göteborgs-Posten daily.
The traffic situation in Gothenburg has been further complicated by the Gothia Cup youth football tournament which is being held in the city.
The Gothia Cup , or World Youth Cup, is the world's largest youth football tournament for those aged 11-19-years-old. Each July some 1,600 teams from more than 70 countries descend on Gothenburg to pit their wits on the pitch.
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