Peshawar, Dec 12:  Two children were killed and 16 others injured when a mortar shell exploded inside a seminary in Pakistan’s northwestern Khyber Pakhtunkhwa Province, local police said on Thursday. The incident occurred in the Esuri area of Mirali tehsil, North Waziristan district bordering Afghanistan, on Wednesday. Some students brought an abandoned mortar shell they had found outside the seminary, Madrassah Shams-ul-Quran, in Sher Mohammad Kot village, which later exploded. According to initial reports, the children mistook the device for a toy and were playing with it when it went off. The explosion left two young children dead on the spot, while 16 others sustained injuries. The wounded were shifted to hospitals in Bannu and nearby areas for treatment. Authorities are investigating how the unexploded ordinance ended up near the seminary. Dozens of children, mostly in northwest Pakistan, have lost their lives in the past when playing with things that turned out to be explosive devices.