Finnish police arrested five people in a Turku apartment overnight in their investigation into a stabbing rampage that left two people dead.

Police shot and wounded a knife-wielding suspect on Friday, arresting him minutes after an afternoon stabbing spree at a Turku market square.

Police on Saturday raised the number of injured in the attack from six to eight.

Police have not confirmed the identity of the suspect and have so far only described him as a young man of Foreign Origin.

The suspect is being treated in hospital in intensive care for a gunshot wound to the thigh.

Meanwhile, people placed flowers in the square in Turku where the attack took place.

Finland is usually peaceful but the security intelligence service raised the terrorism threat level in June, saying it had become aware of terrorism-related plans in Finland.