Montenegro has declared three days of national mourning after 10 people, including two children, were killed in an attack by a 34-year-old gunman in the western city of Cetinje.
The police on Saturday said the attacker used a hunting rifle to first shoot to death two children and their mother, who lived as tenants in his house.
He then walked to the street and randomly shot 13 more people, seven of them fatally.
The gunman was shot dead later after a gun battle with police.
Police investigating the rampage issued a statement on Saturday saying it was still unclear what motivated the gunman.
They added that people close to the attacker said he had recently started exhibiting a change in behaviour but nothing that indicated he could commit such a crime.
The attacker had an appointment to see a mental health care specialist but went on rampage prior to it.