Finnish police are investigating Friday's wild knife attack that killed two and injured eight in the western city of Turk as a crime related to terrorism, they said on Saturday.
"Due to information received during the night, the Turku stabbings are now being investigated as murders with terrorist intent," the National Bureau of Investigation said in a statement.
The suspect was an 18-year Moroccan, police added. The two people killed were Finns, and an Italian national and two Swedes were among the wounded.
Following the attack on Friday, police subdued the suspected attacker after shooting him in the leg but they have not released his name. He is currently hospitalized under guard.
Four other individuals were detained and held overnight in relation to the case, public broadcaster YLE reported, although it was unclear what, if any, involvement they had.
Police said they were working with colleagues from law enforcement abroad, without naming which countries were involved.
Security was reinforced nationwide with increased patrols and more surveillance in case more people were involved.
Flags were at half mast on Saturday across the Nordic country where violent crime is relatively rare. Still, the Security Intelligence Service raised the terrorism threat level in June to 'elevated' from 'low', saying it had become aware of terrorism-related plans in Finland.