All schools have been ordered to close in Nigeria's north-western Zamfara state following the latest mass abduction of students.

On Wednesday morning armed men on motorbikes and pick-up trucks stormed a secondary school.

A teacher said 76 students, most of them girls, and a member of staff had been taken.

Reports say more children may have been seized as 400 were enrolled at the school.

At least one child was critically injured when the gunmen opened fire, the reports say.

Kidnappings of schoolchildren continue in northern Nigeria despite the deployment of thousands of troops.