Two people died and four people were injured in the collision of a motorboat and a sailboat in the Archipelago Sea in southwest Finland on Saturday evening, 3 August. The crash took place in a stretch of the open sea known as Airisto, near the city of Turku.
Southwest Finland police say the impact killed two middle-aged men that were passengers on the sailboat.
Traffic rules for people moving about on the water require that motorboats give the right of way to sailboats, but the police would not provide more information at this stage about the collision, or say whether the deceased were thrown overboard in the incident.
Director Veli-Pekka Nurmi from Finland's Accident Investigation Board says a preliminary investigation has been started.
Initial inspection has ruled out a technical fault, he says, so the investigation will probably look closely into the behaviour and action of the boaters and rescue personnel in question.
The West Finland Coast Guard branch reported on their Facebook page on 4 August that the previous day had been "a difficult one in many ways", with many simultaneous issues to respond to.
Nine people were involved in the accident: two adults in the motorboat and seven others in the sailboat. Two of the sailboat passengers were children.
The crash will be investigated as a case of aggravated traffic safety endangerment and aggravated manslaughter.