Ankara: A former student opened fire at a high school in southeastern Turkey on Tuesday, injuring at least 16 people before taking his own life, officials said.

The 18-year-old attacker, armed with a shotgun, opened fire indiscriminately at a vocational high school in Siverek, located in Sanliurfa Province. He later retreated inside the building and killed himself with the same weapon, Governor Hasan Sildak said.

Among the injured was a teacher who is reported to be in serious condition, according to NTV television.

Authorities said the motive behind the attack remains unclear. School shootings are considered rare in Turkey.

Police special operations teams were deployed after the gunman refused to surrender. All students and staff were safely evacuated from the premises.

Local governor Hasan Sildak told reporters that the attacker was a former student at the school, born in 2007.

“He took his own life when cornered by police,” the governor said.

“We have evacuated the school and will carry out a thorough investigation into this tragic incident,” he added.