Karachi: Grenade hurled at North Nazimabad school
The unknown attackers also left a threatening letter outside the private school premises before fleeing from the scene.
The grenade was hurled when the academic activities were continued in the school.
Terrified parents after hearing about the attack rushed to the school to take their children to home as the school management announced leave after the incident.
According to the bomb disposal squad the grenade was a locally made device in which 500 grams of explosive material was used.