A man is suspected of having killed his two small children in Rovaniemi on Thursday 12 August, according to local police.
The following day Lapland District Court ordered the 37-year-old held on remand on suspicion of the homicides of his two children, both under school age.
Police said an ongoing preliminary investigation would examine the course of events that led to the children's deaths.
There are no other suspects, according to police, who noted that the victims' family members were offered crisis assistance.
Due to the sensitive nature of the incident, police said they would not provide further information about the criminal case.