Officials say 20 nursery school children died in Niger on Tuesday in a fire that trapped them in straw-hut classrooms.

“There were 20 deaths, most of them young children,” said the head of Niger’s fire service, Col. Bako Boubacar.

He said the origin of the fire in Niamey was unknown.

An official of a Niger’s teachers union said the school in the popular Pays Bas neighbourhood had around 800 students, including children in the nursery section.

“The fire apparently started around the school gate. Without an emergency exit, many were trapped and students were forced to scale the wall to escape.

”Those that died were mostly children in the preschool,” Mounkaila Halidou said.

Authorities had arrived at the scene and launched an investigation, the government said.