MORE THAN 600 pupils were evacuated from Royston High School yesterday amid fears there was a chemical or gas leak.

Some 32 pupils and an adult were taken to Barnsley Hospital for check-ups. Most of them were allowed home but last night two pupils remained in hospital.

Police, fire crews and paramedics arrived after being alerted by the school at about 11am.

The fire brigade wearing chemical suits and breathing apparatus evacuated staff and pupils.

After an examination of the school, they could not find any traces of a leak.

Station manager at Royston, Mick Mason, said: “We ruled out carbon monoxide almost straight away and and we found no evidence to suggest the leak was chemically induced.

“Firefighters wore breathing apparatus purely as a precautionary measure because, at that time, we didn’t know what was involved.”

The cause of the incident is still unknown.

The drama started at about 10.45am when three pupils in a science lesson complained of feeling faint. They were watching a video about the human body.

Headteacher Kay Jenkins said the film was not gory and was not about sex education or childbirth. A couple of other pupils in another part of the school also started to feel unwell.

Ms Jenkins added: “We have shown the video many times before. It is an old Channel 4 programme about the human body and muscles but it wasn’t gory.

“We are still at a loss. There is no evidence of carbon monoxide and a full check was done by the fire service. If there had been a (health and safety) issue we would not have been back in school.”