At Least 10 Dead, Including 2 Young Brothers, in New Year’s Day Shooting in Montenegro

A gunman went on a deadly, 30-minute rampage in Montenegro on New Year’s Day, killing 12 people in the small Balkan nation, including two children and the shooter’s own sister, authorities said.

The shooter, identified as Aleksandar Aco Martinovic, 45, died of a self-inflicted gunshot wound following an intense manhunt, Reuters reports.

The massacre, considered one of Montenegro’s deadliest mass shootings, began at a tavern in the city of Cetinje in southern Montenegro, according to RTCG, the country’s national broadcast station.

Martinovic “had consumed alcoholic beverages all day long” when got into an argument with someone at the restaurant, Acting Director of the Police Administration Lazar Scepanovic said, Reuters reports.

He went home and retrieved a weapon before returning to kill four people at the restaurant and then going to the other locations, Scepanovic said, according to the BBC.

He widened his spree, driving to five other locations, where he shot and killed eight other people, including the two children, prosecutor Andrijana Nastic said, RTCG reports.

“All the victims were his godfathers, friends… the motive is still unknown,” Scepanovic said, Reuters reports.

One of the victims was his sister, Zorica Vuletić, according to RTCG.

The children he killed were brothers, ages 14 and 9, according to RTCG.

The rampage lasted 30 minutes, Scepanovic said, RTCG reports. Police were initially sent to the wrong location, he said, according to the outlet.

Want to keep up with the latest crime coverage? Sign up for PEOPLE‘s free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.

“The location in the town of Bajice was pointed out, where the police were sent at 17:31 and they determined that it was not the scene of the incident,” he said. “On that occasion, the police were sent to the wrong location.”

Police located Martinovic near his house, where he shot himself in the head, Scepanovic said, RTCG reports.

“When he saw that he was in a hopeless situation, he attempted suicide,” he said. He died on the way to the hospital.

The gunman was no stranger to law enforcement and has a history of illegal gun possession, police said, RTCG reports.

Montenegro is observing three days of national mourning starting on Thursday.

Prime Minister Milojko Spajic said the massacre “shrouded our country in black,” the BBC reports.

The shooting spurred Spajic to call for a review of the country’s gun ownership laws.

According to the BBC, he said the nation’s security council would hold an emergency meeting on Thursday, Jan. 2,  to “urgently consider all options” to protect the public, including a complete ban on the possession of weapons.