Finland's National Bureau of Investigation (NBI) confirmed on Saturday that the previous day's knife attack in Turku is being investigated as murder and attempted murder with a terrorist intent.
The main suspect is an 18-year-old Moroccan man. He remains hospitalised in critical condition after being shot in the hip by police.
Police have also released more information about the victims. The two were killed were Finnish citizens. The eight injured include one Swede, one Briton and one Italian citizen. One of the wounded is under age 18.
Four patients may be released on Saturday
Three people remain in intensive care, including the suspected assailant.
One of the injured has been released from Turku University Hospital (TYKS), and four more may be discharged on Saturday.
Police took four other individuals into custody overnight. They are being interviewed on Saturday.
The NBI provided more details at a press conference on Saturday afternoon.
NBI said that the three foreigners injured in Turku were from Britain, Sweden and Italy, rather than just Sweden and Italy as they previously said. The Italian is a 30-year-old woman, a university researcher who has lived in Turku for a few years. She was stabbed in the shoulder, but not seriously injured.
When police confronted the attacker, he ignored a verbal order and was then immobilised with a single shot to the leg. The assailant was given first aid and taken into custody.
Suspect was "involved in the asylum seeking process"
The man is a Moroccan, as are four other detainees. The main suspect has so far been unwilling to speak to police, who plan to try again later on Saturday.
Both of those killed were women. The injured include six women and two men. The men had tried to intervene. Police believe the attacker apparently specifically targeted women, but otherwise chose his victims at random.
Some of the victims have serious injuries, but none are considered life-threatening. The victims ranged in age from 15 to 67.
The Jehovah's Witnesses said on their website that one of their members had been killed.
The four others were detained in Turku at one or more private homes and at an asylum-seekers' reception centre. An international warrant has been issued for a fifth Moroccan.
A van belonging to one of the suspects has been seized, but police could not say how or whether the vehicle was directly involved in the attack.
Police say the main suspect arrived in Finland early last year and was "involved in the asylum seeking process" - but say they cannot provide further details.
International links unclear
The suspected attacker was living at a reception centre for asylum seekers in Turku.
The NBI believes that the attack was planned in advance to some degree, but declined to speculate on how organised it was, or any possible links to international groups.
The Finnish Security Intelligence Service (Supo) later on Saturday afternoon called this the first suspected terrorist attack in Finland, but added that the overall risk level in the country has not significantly changed.
Europol is looking into whether there were any possible connections between the Turku incident and two deadly terror attacks in Spain on Thursday and Friday. Some of the suspects in those attacks are or were Moroccan men of around the same age as the Turku suspect.