The shootings on Wednesday in a school in Belgrade and on Thursday in a rural area south of the capital city have left the nation stunned with grief and disbelief.

Though Serbia is awash with weapons and no stranger to crisis situations following the wars of the 1990s, a school shooting like the one on Wednesday has never happened before. The most recent previous mass shooting was in 2013 when a war veteran killed 13 people.

The shooter on Wednesday was a 13-year-old boy who opened fire on his fellow students, killing seven girls, a boy and a school guard. A day later, a 20-year-old man fired randomly in two villages in central Serbia, killing eight people.

While the country struggled to come to terms with what happened, authorities promised a gun crackdown and said they would boost security in schools.

Thousands lit candles and left flowers near the shooting site in Belgrade, in an outpouring of sadness and solidarity.

Serbian media reported that four of the eight children killed in the school shooting, as well as the Vladislav Ribnikar school guard, will be buried at cemeteries in Belgrade on Saturday, the second day of a three-day mourning period for the victims.

Some 50 kilometers (30 miles) to the south, a mass funeral service will be held in the small village of Malo Orasje for five young men who were gunned down in the shooting rampage on Thursday evening. Villagers told Serbian media the tragedy is too huge to handle.

“Five graves! He (the killer) shut down five families,” one villager told N1 television. “How could this happen?”

Serbian police have said that the suspected shooter stopped a taxi after his rampage and made the driver to take him to a village further south, where he was
arrested on Friday. Officers later said they found weapons and ammunition in two houses he was using there.

The motive for both shootings remained unclear. The 13-year-old boy has been placed in a mental clinic, too young to be criminally charged. His father was arrested for allegedly teaching his son to use guns and not securing his weapons well enough.

The suspected village shooter wore a pro-Nazi T-shirt, authorities said, and complained of “disparagement,” though it was unclear what he meant. Populist leader Aleksandar Vucic promised the “monsters” will “never see the light of day again.”

The wounded in the two shootings have been hospitalized and most have undergone complicated surgical procedures. A girl and a boy from the school shootings remain in serious condition, and the village victims are stable but under constant observation.

School shooting left six children and a teacher wounded, while 14 people were injured in the villages of Malo Orasje and Dubona. The dead in Dubona included a young, off-duty policeman and his sister.

Authorities released a photo showing the suspected shooter upon arrest — a young man in a police car in a blue T-shirt with the slogan “Generation 88” on it. The double eights are often used as shorthand for “Heil Hitler” since H is the eighth letter of the alphabet.

Experts have repeatedly warned that decades of crises and economic hardship, coupled with corrupt institutions and a high level of intolerance in public speech and politics, could push some people over the edge.

The populist-led Balkan country has refused to fully face its role in the wars of the 1990s, war criminals are largely regarded as heroes and minority groups routinely face harassment and sometimes physical violence.

“The question now is whether our society is ready to reject the model of violence,” psychologist Zarko Korac warned. “When you glorify a war criminal you glorify his crimes and you send a message that it is legitimate.”