A man killed 12 people including two children in a shooting rampage in Montenegro before turning the gun on himself.

The attacker, identified as 45-year-old Aleksandar Aco Martinovic, initially killed four people when he opened fire at around 5.30pm after a dispute at a restaurant in the small western town of Cetinje on Wednesday afternoon.

He then shot dead eight people, including two children, at three other locations, prosecutor Andrijana Nastic said.

The restaurant owner and his children were reported to be among the victims, as well as members of the shooter’s own family.

Authorities said the attacker died from self-inflicted wounds on Thursday, ending one of the Balkan nation’s worst mass killings.