Manchester Grammar pupils 'poisoned' during scuba diving lesson Published duration 28 June 2017

image copyright Other image caption The boys were taking part in a scuba diving lesson at Manchester Grammar School on Monday

Twelve pupils have been treated for carbon monoxide poisoning after becoming ill during a school scuba diving lesson, police have said.

The group of boys at Manchester Grammar School in Fallowfield were taken to hospital at about 15:10 BST on Monday.

Eleven were later discharged following treatment, while one, aged 14, remained in hospital in a stable condition.

Greater Manchester Police are investigating whether carbon monoxide was present in the boys' air tanks.