There were about 20 people on the commuter train when it derailed off the tracks at an intersection on Storgata, one of the Norwegian capital's main thoroughfares close to Oslo's main train station

Witness Mohnsin Munir told Norwegian media that he saw the tram coming at high speed. It was supposed to make a left turn but derailed and continued straight ahead and into the shop

Police said that the tram driver is considered a suspect in the case. The driver was not identified

Images from the scene show that most of the first carriage of the tram had slammed into the shop. Police and the fire department said the crash had caused extensive damage in the shop

The tram driver was among those injured. Police said everyone was treated at the scene but no one had serious injuries