At least one minor girl died and three others sustained injuries in a roadside blast in Spinwam tehsil of North Waziristan on Monday, DawnNews reported.
Security sources said the Improvised Explosive Device (IED) was planted next to the school gate which went off when the gate was opened.
No classes were taking place today and the children were going to the Abakhel school to play when the bomb planted outside it went off.
The injured were shifted to Mir Ali Hospital and Miranshah Hospital.
Operations against militants in North Waziristan were stepped up after the government decided to implement the nation-wide National Action Plan for combating terrorism in the country. Suspected militants have also been killed in drone strikes in the region.
Zarb-i-Azb military operation which targeted local and foreign militants specifically in North Waziristan was spearheaded following an attack on Karachi's Jinnah International Airport on June 8, 2014.
According to official statements, over 3,500 militants have been killed in operation Zarb-i-Azb, while the offensive forced over a million civilians to vacate their homes and move to settled areas of the country.
The number of attacks in the country has fallen around 70 per cent but attacks on security and civilian targets continue to occur occasionally.