Three women – a local politician and two journalists – have been shot dead in Finland as they left a restaurant.

The motive for the killings in the early hours of Sunday in the south-eastern town of Imatra is unclear. A local man aged 23 and with a criminal record has been arrested.

Police said it appeared the victims had been chosen at random. The local politician was named as Tiina Wilen-Jappinen, the chairwoman of Imatra’s town council.

A rifle was used to carry out the shootings, police said, and the alleged perpetrator was detained almost immediately.

The victims had all been shot in the head and torso, Finland’s national broadcaster YLE reported. Two of the victims, including Ms Wilen-Jappinen, are reported to have been in their 50s and one in her 30s.

Crime levels are relatively low in Finland, but the country has one of the highest rates of gun ownership in the world, with hunting a popular pastime.