Unknown attackers targeted the premises of Government Model High School in Pakistan's Kharan region during a training session for polling staff on Monday.

According to reports, the attackers hurled a grenade inside the premises of the school.

The powerful blast shattered the windowpanes of some classrooms, causing a disturbance in the vicinity, Dawn News reported.

The government officials and election commission staff remained unharmed.

Law enforcement officials rushed to the spot after the blast and cordoned off the area.

An investigation has been initiated.