An overnight shooting incident in Hyvinkaa, a small town in southern Finland, on Saturday morning has left two dead and seven injured.

According to Finnish media, the incident began in the center of the town of roughly 45,000 inhabitants at around 01:50 am local time (GMT 2250).

A young man dressed in military fatigues opened fire at restaurants and shop with two weapons, one of them a large-caliber 7.62 mm hunting rifle, from the roof of a building in the town, around 50 km north of the Finnish capital Helsinki.

An 18-year-old woman was killed. Another victim, a 19-year-old man, died later in a hospital. Both victims were students at the Hyria Vocational Institute and were to graduate this summer.

The seven injured have been hospitalized, including a 23-year-old woman police trainee, who is still in critical condition.

The dead 19-year-old man and two injured people were members of the local Hyvinkaa Finnish-rules baseball team. The Finnish-rules baseball premier league program for this weekend has been cancelled following the tragedy.

Police units arrived on the scene within minutes after the alarm was raised. The operation involved around 50 police officers, including members of a rapid-response team.

Shortly before 8 am (GMT 0500) on Saturday morning, the 18-year-old suspect was arrested.

During initial questioning by police, the suspect admitted that he had carried out the shootings. The head of the investigation Mika Ihaksinen of the Finnish National Bureau of Investigation said on Saturday afternoon that it was too early to speculate about the gunman's possible motive.

The gunman had stolen the weapons from a private home, Ihaksinen was quoted by Finnish newspaper Iltasanomat as saying.

Police said there was a single shooter, but it is possible that there were some other people involved.

Finnish President Sauli Niinisto expressed his condolences to the victims and their families in an early morning television interview.

Interior Minister Paivi Rasanen praised the police for handling the incident swiftly and successfully. She said the incident will give even more food for thought to a working group that is currently reviewing reforms of the nation's gun laws.

Rasanen said regulations on the storage of firearms could get stricter. In future, the law may require that all firearms should be kept locked in a secure gun cabinet when not in use.