Police in Kano have said that the explosion in Sabon Gari area of Kano was caused by a gas cylinder.
They also confirmed that four persons died in the incident while many sustained injuries.
The incident happened at about 9 a.m. after the children have marched into their classrooms for the day’s work.
The school building collapsed and many children in school uniform were seen rushing out with blood stains.
It is not immediately clear how many were trapped or injured in the explosion.
Samaila Dikko, the state Commissioner of Police said in a radio and television broadcast in Kano that
the gas exploded at a welding point near a primary school on Aba Road in Sabon Gari, Kano.
He said that rescue workers were making efforts to discover people trapped at the building where the explosion occurred.
Dikko urged residents of the state to remain calm as the situation was under control.
Meanwhile, the Kano State government has clarified that the early Tuesday morning explosion in the Sabon Gari area did not occur in a school.
Security operatives have visited the scene but there is no official statement from the government yet.