At least 11 people have been killed in a shooting following a family dispute in the city of Cetinje in Montenegro.

According to officials, a single gunman shot dead three members of the same family before shooting at passers-by.

A mother and her two children all staying in the shooter's house were killed, prosecutor Andrijana Nastic told journalists.

The attack finally ended when the 34-year-old gunman was shot dead by a civilian.

After killing three members of the same family who were staying at his house, officials said the gunman left the property and fatally shot seven local residents using the same hunting rifle.

"For now, it is not clear what prompted [the suspect] to commit such a heinous act, on which occasion he himself was deprived of his life," Ms Nastic told a press conference on Friday evening.

Another six people are currently being treated in hospital.

Prime Minister Dritan Abazovic said the government was declaring three days of mourning following the tragedy.

"I invite all the citizens of Montenegro to be with the families of the innocent victims," he wrote on Telegram.

The city of Cetinje is home to the picturesque Adriatic nation's former royal capital, and is situated in a mountainous valley around 36km (22 miles) west of the capital Podgorica. (BBC)