Children have been forbidden to carry mini-lasers disguised in pens on school buses in Northamptonshire.

The ban follows an incident in which a bus driver was injured by the laser reflecting in a wing mirror.

Olwen Loud, the county's cabinet member for education, said: "A child brought one of these laser pens on the bus, and it shone at the driver's mirror and reflected the laser beam back into one of his eyes."

She said the driver was hospitalised but did not suffer any permanent damage.

But she added: "We know of another case elsewhere in the country where a driver on a school bus had his sight so badly damaged he had to give up his driving job. "

Schools have been asked to educate youngsters on the dangers of the laser pens.

The instruments are used as electric pointing sticks by lecturers and release a thin beam with a range of up to 200ft (61m).