A police officer shot a man in the leg on Friday evening in the eastern port city of Kotka.
Officers were responding to a domestic alarm around 11pm when they say a man threatened them with a weapon.
“To overcome his resistance, police shot the man in the leg,” the Southeast Finland Regional Police Department said in a statement.
The man was still in hospital on Saturday, but his injuries were not described as serious. One of the officers was also treated in hospital for injuries incurred during the use of force.
The confrontation took place in Alakylä, some 13 km north of the city centre.
The district prosecutor has begun a probe of the incident.
Finnish police fire their guns in the line of duty about 10 times a year on average. Seven people have been killed by police bullets since the turn of the millennium, most recently near Tampere in April.