Police on Thursday arrested a man suspected to have set fire to a residence at Kullervonkatu in Lappeenranta.
Police said the fire took place at about 4:30am on Thursday, when three people were present in the house.
A team of patrol police rushed to the spot immediately after the incident and called in the fire brigade to douse the blaze.
The suspected arsonist, who was drunk, tried to flee after the incident but police nabbed him.
The 29-year-old man admitted to have launched the arson attack on the house.
Police are investigating the motive of the crime.
The house is still habitable, they said.
