File photo: Gun

A teenage boy opened fire in a school in the Serbian capital of Belgrade just after lessons began on Wednesday morning, killing eight children and a security guard and seriously injuring several others, officials said.

The boy – a 13-year-old student at the school – allegedly sketched out the attack in advance on crumpled pieces of paper that officials displayed at a somber press conference. He called police himself after the shootings, they said.

The rare and possibly unprecedented event, in a nation with strict firearms laws yet high levels of gun ownership, sent shockwaves through the local community and beyond.

First reports of the shooting emerged not long after students arrived to begin the day at Vladislav Ribnikar Elementary School, a well-known institution in Vračar, an upscale area of the Serbian capital. Panicked parents rushed to the scene.

Seven girls and one boy were killed, alongside the security guard, Belgrade’s Police Chief Veselin Milić said at a press conference. A further six children and one teacher were hospitalized, Serbia’s Ministry of Internal Affairs said.

The suspect opened fire in a history classroom, “because it was near the entrance of the school,” he added.

He killed the security guard first, then went to another classroom where she shot some of his schoolmates, Milić said. The teenager then telephoned the police and waited to be arrested in the schoolyard.

The alleged shooter was later filmed being taken from the school in handcuffs with a jacket over his head and wearing blue, skinny jeans. He was flanked by police officers and driven away in an unmarked police car.

Serbian Interior Minister Bratislav Gasic said that the suspect’s father was also arrested, adding that it was known that he had previously visited a shooting range with his son, whose age was first given as 14.

Parents gathered outside the school as police responded to the shooting.

Parents gathered outside the school as police responded to the shooting.Oliver Bunic/AFP/Getty Images

According to Gasic, the boy brought two guns from home. “The parent had several pieces of weapon and kept them locked up. The safe had a code. Obviously the kid had the code as soon as he managed to get hold of those two guns. And three frames full of 15 bullets each.”

Milić, the police chief, said the boy had a 9mm pistol and a small caliber pistol in a bag, as well as four Molotov cocktails.

Officials said the shooting was premeditated, and displayed sheets of paper that allegedly showed the suspect’s plans for the attack.

Parents struggled to come to terms with the shooting. The father of one student said he ran to the school to look for his daughter after seeing police at the scene, according to CNN affiliate N1.

“My child is still in shock, full of adrenaline, we haven’t been able to calm her down,” a mother of one child told N1.

Another father recounted a chaotic morning. “I was heading to the bank, and I saw a bunch of police. That was around 8:50. I came running. I saw the school psychologist, I saw the school staff, the teachers who were in shock,” the father told N1.

“The police came quickly, from what I could see. I asked: ‘Where’s my kid?’ And allegedly, one man said that the history teacher was shot. I went back to my apartment to look at my child’s schedule, and she was actually in history class. I took my wife with me and we went back out on the street,” he said.

“I saw that the security guard was lying under a table, in a circle [of blood] I went through the door looking for an attendant. I didn’t know what to do. I asked ‘Where’s my kid?’ and no one was saying anything,” the father said.

Police officers escorted the alleged shooter from the school.

Police officers escorted the alleged shooter from the school.Oliver Bunic/AFP/Getty Images

The man later learned that his daughter had escaped unharmed.

The interior ministry said in a statement on Facebook that it was told of the incident at 8.40 a.m. local time (2.40 a.m. ET). “All available police patrols were dispatched to the scene, where they immediately went onto the school grounds and apprehended a minor, a seventh-grader who is suspected to have fired several shots from his father’s gun at students and the school security guard,” the statement said.

A schoolgirl injured in the shooting has life-threatening wounds and was undergoing surgery, N1 reported.