BELGRADE, Serbia (AP) — A gunman killed eight people and wounded 14 in two villages in Serbia, authorities said, shaking a nation still in the throes of grief over a mass shooting at a school a day earlier. Police arrested a suspect Friday after an all-night search.

Serbian President Aleksandar Vucic called the shootings late Thursday an attack on the whole nation . Vucic said the suspect wore a T-shirt bearing a pro-Nazi slogan, but he did not speculate about the motive. Police said the suspect was a man born in 2002.

The slayings came a day after a 13-year-old boy used his father’s guns to kill eight fellow students and a guard at a school in Belgrade, the capital.

The back-to-back bloodshed sent shockwaves through a Balkan nation scarred by wars, but unused to mass murders. Though Serbia is awash in weapons left over from the conflicts of the 1990s, the last mass shooting before this week was in 2013, when a war veteran killed 13 people in a central Serbian village.

Public figures, politicians and experts appeared successively on TV Friday, desperately trying to explain the tragedies. The first made the country numb with grief, while the second heightened anxiety over what might come next — and set off soul-searching in a deeply divided nation where convicted war criminals are frequently glorified and violence against minority groups often goes unpunished.

“This is a moment when a nation decides whether it will go along a healing path,” actor Srdjan Timarov said on N1 television. “The only other way is to declare capitulation.”

As a nationwide period of mourning began, TV screens were filled with people wearing black and music was banned from the airwaves as well as in cafes and restaurants. People lined up in Belgrade to donate blood, responding to an appeal for supplies needed to treat the wounded. TV stations featured experts offering coping advice and strategies for discussing the tragedies with children.

Thursday’s attack unfolded near Mladenovac, a municipality located about 50 kilometers (30 miles) south of the capital, where the assailant first killed five people and wounded six in one village before killing three more and wounded eight in the other, according to police.

Vucic said the gunman targeted people “wherever they were.”

In the village of Dubona, blood stained a schoolyard where some of the shots were fired and also a piece of ground by a bench where residents often sit to share a beer and chat.

“I heard some tak-tak-tak sounds,” recalled Milan Prokic, a Dubona resident. Prokic said he first thought people were shooting to celebrate a birth, as is tradition in Serbia.

“But it wasn’t that. Shame, great shame,” Prokic added.

After the shootings, the suspect hijacked a taxi and forced the driver to take him more than 100 kilometers south to Vinjiste, the village where he was eventually arrested, police said. Officers found a large stash of ammunition and illegal weapons, including hand grenades, an automatic rifle and handguns, while searching a relative’s home and a cottage in yet another village.

Authorities released a photo showing 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.

Vucic said the suspect repeated the word “disparagement” but it wasn’t clear what that meant.

The president vowed in an address that the suspect “will never again see the light of the day.” He referred to the attack as an act of terror and announced tougher gun-control measures, on top of ones put forward by the government a day earlier.

He called for a moratorium on new licenses for all weapons in the next two years, a review of all current licenses, longer prison sentences for those who break the rules and “fierce” punishment for anyone caught with illegal weapons. But first police will offer an amnesty to encourage people to hand over illegal guns — an action that has had limited success in the past.

“We will disarm Serbia,” Vucic promised, saying the government would outline the new rules later Friday.

Health Minister Danica Grujicic said the wounded included a teenage girl who was hit in the head and another teen who had to have a kidney removed.

“We haven’t seen this since the 1990s (war era),” the minister said. “They are stable for now but you can never tell for sure with gunshot wounds.”

While the Serbian government sought to crack down on guns and police raced to investigate the fresh violence, the nation started to ask what social factors may have contributed to the mass shootings. Serbia has one of the highest number of firearms per capita in the world, and guns are frequently fired into the air to mark the birth of a child or other special occasions.

Experts have repeatedly warned of the danger posed by those weapons coupled with decades of instability stemming from the conflicts of the 1990s, as well as ongoing economic hardship.

Belgrade University psychology professor Dragan Popadic pointed to various forms of violence coursing through society, including harassment of political opponents by ruling populists and aggressive hooligan groups in sports.

“People suddenly have been shaken into reality and the ocean of violence that we live in, how it has grown over time and how much our society has been neglected for decades,” Popadic told The Associated Press in the wake of the first shooting. “It is as if flashlights have been lit over our lives and we can no longer just mind our own business.”

Some commentators called for state-backed teams to work on violence prevention. Opposition parties called for a march against violence on Monday, urged the government to control media content and demanded the resignations of three ministers.

“Serbia is not a powder keg. Serbia has exploded,” said Marinika Tepic, the vice president of an opposition party.

Before the latest attacks, Serbia spent much of Thursday reeling from the shooting at the Vladislav Ribnikar school in Belgrade. Students, many wearing black and carrying flowers, filled the streets around the primary school, paying silent homage to their slain peers. On Friday, residents waited in a long line outside the school to sign a condolence book.

Serbian teachers’ unions announced protests and strikes to warn about a crisis in the school system and demand changes.

The attack at the school also left seven people hospitalized, six children and a teacher. One girl who was shot in the head remains in life-threatening condition, and a boy is in serious condition with spinal injuries, Grujicic said Friday.

Authorities have said the suspected shooter, Kosta Kecmanovic, was too young to be charged and tried. He has been placed in a mental hospital, and his father has been detained on suspicion of endangering public security.