Unidentified armed motorcyclists hurled grenades at a private school in Karachi early Tuesday. However, no casualties have been reported as the students were not in the premises.

The police, who arrived at Karachi's Gulshan-e-Iqbal school immediately to gather evidence, found a letter that was left behind by the attackers, reports Pakistani news channel Geo TV.

Provincial Education Minister Nisar Khuhro has sought an investigative report regarding the grenade attack from the police.

Although all schools and other academic institutions in the area have been asked to suspend operations, DIG-East Munir Sheikh confirmed that schools were not directly targeted by the assailants and that the grenades landing close to the school was only coincidence.

Officials believe that the attack is in retaliation for Pakistan hanging two terror convicts affiliated with the extremist group Laskhkar-i-Jhangvi at the central prison in Karachi.

The grenade attack is reportedly meant to create panic among children and parents, especially since the general public is still reeling from the deadly massacre at Peshawar Army School on 16 December 2014.

Pakistan School Attack
A soldier escorts schoolchildren after they were rescued from from the Army Public School that is under attack by Taliban gunmen in Peshawar, December 16, 2014.Reuters