Norwegian police said they shot and wounded the man who reportedly stole an ambulance and hit several pedestrians as he drove away.
Broadcaster NRK reported that a baby in a pram was among the injured and has been taken to hospital.
The report added that police are looking for another person who may have been involved, though authorities would not confirm the report.
Police said the man was later arrested, but did not state whether the incident was being treated as a deliberate attack.
The incident took placer in the northern part of Oslo, the Norwegian capital.
