At least nine people have been killed after a teenager opened fire at an elementary school in Serbia. A security guard and eight students were killed following the shooting at a school in Belgrade on Wednesday morning.

Police said eight children and a security guard were killed when a teenage boy opened fire at a school in Serbia's capital of Belgrade on Wednesday.

Serbia's interior ministry confirmed the death of eight students and a security guard. Six more children were hospitalized along with a teacher, according to the ministry's statement.

The shooting occurred at 8:40 am local time (06:40 GMT) in the Vracar district of the Serbian capital. The student reportedly opened fire in a classroom during a history class.

"The police sent all available patrols immediately to the spot and arrested a suspected minor — a seventh grade student who is suspected of firing several shots from his father's gun in the direction of students and school security," the ministry said in a statement.

Police were investigating a motive. "All police forces are still on the ground and are intensively working to shed light on all the facts and circumstances that led to this tragedy," the ministry added. 

"I was able to hear the shooting. It was non-stop," a student who was in a sports class downstairs when the gunfire erupted. "I didn't know what was happening. We were receiving some messages on the phone."

One of the children who witnessed the shooting told her father she was in the classroom when the shooting began.

"She managed to escape. (The boy) ...first shot the teacher and then he started shooting randomly," the girl's father, Milan Milosevic, told broadcaster N1.

Milosevic rushed to Vladislav Ribnikar elementary school when the shooting was first reported. 

"I saw the security guard lying under the table. I saw two girls with blood on their shirts. They say he (the shooter) was quiet and a good pupil. He recently joined their class," he said.

Footage from the scene showed commotion outside the school as police removed the suspect, whose head was covered as officers led him to a car parked in the street.

Mass shootings are rare in Serbia and purchasing a firearm requires a special permit.

However, many firearms left over from the wars of the 1990s are still in circulation.

The last mass shooting in Serbia happened in 2015 when Sinisa Zlatic killed five people and wounded twenty-two with an assault rifle in a cafe in the town of Zitiste.