The fire started when the teacher struck a match to light the classroom's gas heater, Geo News reported.
Firefighters arrived on the scene and put out the flames, a rescue official said.
The injured children, all between 10 to 12 years old, and have been admitted to Mayo Hospital, the news report said.
Sign language interpreter at Mandela service called out as fake on Twitter
N.J. man wakes up from 10-hour sleep with knife in back