PODGORICA, Montenegro - A shooter killed at least 11 people including two children in a mass shooting in Montenegro's central city of Cetinje on Friday, officials said, in one of the deadliest violent incidents to rock the Adriatic nation.

"Eleven people were killed in Cetinje today," Andrijana Nastic, a government prosecutor helping oversee the investigation into the incident, told reporters, saying the shooter was among the dead.

"Two children are among the victims," she added.

A police officer, who spoke on condition of anonymity, also confirmed the figure to AFP.

The incident took place in Cetinje, around 36 kilometres (22 miles) west of the capital Podgorica, after the shooter was involved in a family dispute, according to public broadcaster RTCG.

The shooter was believed to have been killed by a local resident, according to Nastic, dispelling earlier reports that said the gunman had been shot by police.

Six people were also wounded in the attack, with three in a critical condition, according to Ljiljana Radulovic -- the director of the central hospital in Podgorica, told reporters.

In the shooting's wake, Prime Minister Dritan Abazovic called on the country to offer support to the families of the victims, saying the incident was unprecedented in Montenegro's recent history.

"I invite all the citizens of Montenegro to be with the families of the innocent victims," the prime minister wrote in a post on Telegram.

Hours after the attack, Abazovic declared three days of mourning in the country.

- Reeling with shock -
Montenegro is famed for its picturesque beaches, framed by nearby mountains that have long been a draw for tourists.

Cetinje is the site of the country's former royal capital and lies in a mountainous valley that has largely stagnated economically in recent decades.

Residents were left in shock in the shooting's wake.

"I can’t believe that this happened in Cetinje and Montenegro. I do not know what to say, I am speechless. I do not know where this can lead us,” said Cetinje resident Milorad Mitrovic to public broadcaster RTCG.

The incident comes as the country is in the full throes of its highly anticipated tourism high season following two years of the coronavirus pandemic.

With an unemployment rate of some 18 percent and an average monthly salary of under 520 euros ($533), Montenegro counts on tourism and the appeal of some 300 km of azure coastline to boost its revenues.

Holiday destinations such as Budva and Kotor draw big crowds, the latter appearing on the UNESCO world heritage list.

Organised crime and corruption have remained two major issues plaguing the country which authorities have pledged to tackle under pressure from the EU.

Mass shootings, however, have been rare in the Adriatic nation.