A police officer was shot while on duty on Friday night in the south-central city of Hämeenlinna.
In a press release, Häme police said that the incident occurred around 11.30 pm in the courtyard of a block of flats while officers were responding to a call. In response, they said, "police used a service weapon to stop a dangerous person".
Police said that the operation was still in progress as of about 3:30 am Saturday.
According to the police, the situation was by then under control and no one was in danger any longer.
The police declined to comment further on the matter at that stage, but promised to provide more details later.
The prosecutor on duty was informed of the incident, as required whenever a service weapon is used in the line of duty, Häme police said.
The case has been handed over to the National Bureau of Investigation (NBI). It said later on Saturday that the police officer had been released from hospital, but declined to release more details, citing the ongoing investigation.
It is being treated as a case of attempted murder.
Hämeenlinna is a city of 68,000, about 100 km north of the capital, Helsinki.
Officers shot a month ago in Rusko
The most recent shooting of police officers took place in Rusko, Southwest Finland, on 23 August. According to a preliminary investigation by the NBI, three police officers faced a life-threatening situation. The gunman was shot by police and died in hospital.
Two years ago, two police officers were wounded in Porvoo by two Swedish brothers, who also fired at police during a car chase in Pirkanmaa.
In mid- 2016, one police officer was killed and another wounded with an assault rifle in Vihti. In 2012, police in Hyvinkää were wounded during a shooting incident that left two people dead.
14.20: Updated with more details.