KARACHI: Unknown motorcyclists hurled a hand grenade at a school near KDA roundabout in Karachi's North Nazimabad locality Wednesday though no loss of life or property was reported in the incident.

The attackers also dropped a 'threat letter' in the school premises before escaping from the scene.

According to sources, terrified children were told to duck down by school officials after the bomb went off.

Bomb disposal squad personnel present at the scene said 500 grams of explosive material was used in the making of the bomb.

Know more: Schools’ security

A similar incident took place yesterday when unidentified attackers hurled a grenade at a mosque in Karachi's Orangi Town area.

Earlier in February, unknown motorcyclists had hurled a grenade on a road that houses a number of private schools in Karachi's Gulshan-i-Iqbal Block 7 area causing fear and panic among area residents. No loss of life or property was reported in the incident.

Also read: Private schools told to make own security arrangements

Many schools across the country beefed up security following a Taliban attack at the Army Public School in Peshawar on December 16 which had claimed the lives of more than 150 people including 141 school children.

Take a look: Militant siege of Peshawar school ends, 141 killed

Education Minister takes notice

Sindh education minister Nisar Ahmed Khuhro took notice of the grenade attack on the school and ordered a report on the incident from Capital City Police Officer (CCPO) Karachi.

He called for an increase in patrolling of police officials around the school.