BELGRADE, Serbia >> Serbian police said early Friday they had arrested a suspect in a series of shootings that killed at least eight people and wounded 14, the nation’s second such mass shooting in two days.

In a statement, police said that the man, identified by initials U.B., was arrested near the central Serbian town of Kragujevac, about 100 kilometers (60 miles) south of Belgrade.

The shooting 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 bloodshed sent shockwaves through a Balkan nation scarred by wars, but unused to mass murders.

Friday’s arrest followed an all-night search by hundreds of police, who sealed off an area south of Belgrade where the shooting took place late Thursday.

The attacker shot randomly at people in three villages near Mladenovac, some 50 kilometers (30 miles) south of the capital, according to state broadcaster RTS.

“I heard some tak-tak-tak sounds,” recalled Milan Prokic, a resident of Dubona, a village near the town of Mladenovac. Prokic said he first thought villagers were shooting to celebrate a childbirth, as is tradition in Serbia and the Balkans.

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

Serbian Interior Minister Bratislav Gasic called Thursday’s shootings “a terrorist act,” state media reported.

Before the second shooting, Serbia spent much of Thursday reeling from its first mass shooting in ten years. Students, many wearing black and carrying flowers, filled streets around the school in central Belgrade as they paid silent homage to slain peers. Serbian teachers’ unions announced protests and strikes to warn about a crisis in the school system and demand changes.

The same day, authorities moved to boost gun control, as police urged citizens to lock up their guns and keep them away from children. The government ordered a two-year moratorium on short-barrel guns, tougher control of people with guns and shooting grounds, and tougher sentences for people who enable minors to get hold of guns.

A registered gun owner in Serbia must be over 18, healthy, and have no criminal record. Weapons must be kept locked and separately from ammunition.

Though Serbia is awash with weapons left over from the wars of the 1990s, Wednesday’s school shooting was the first in the country’s modern history. The last mass shooting before this week was in 2013, when a war veteran killed 13 people in a central Serbian village.

The shooting on Wednesday morning in Vladislav Ribnikar primary 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, doctors said on Thursday morning.

Authorities have said the shooter, whom police identified as Kosta Kecmanovic, is too young to be charged and tried. He has been placed in a mental institution, while his father has been detained on suspicion of endangering public security because his son got hold of the guns.

Gun culture is widespread in Serbia and elsewhere in the Balkans: The region has among the highest numbers of guns per capita in Europe. Guns are often fired into the air at celebrations and the cult of the warrior is part of national identities.

Experts have repeatedly warned of the danger posed by the number of weapons in the highly divided country, where convicted war criminals are glorified and violence against minority groups often goes unpunished. They also note that decades of instability stemming from the conflicts of the 1990s, as well as ongoing economic hardship, could trigger such outbursts.

Dragan Popadic, a psychology professor at Belgrade University, told The Associated Press that the school shooting has exposed the level of violence present in society and caused a deep shock.

“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,” he warned. “It is as if flashlights have been lit over our lives and we can no longer just mind our own business.”