Police are appealing to parents in a bid to crack down on the recreational use of laughing gas among school children.

It is believed the gas, known as nitrous oxide, is being purchased online and then sold around schools after empty canisters have repeatedly been found littered in Rudloe Park and Meriton Avenue recreation ground.

The gas, which is commonly used as pain relief, is legal to use but illegal to sell to under-18s and police believe the increase is down to it coming in from Bath and Bristol and also from festivals over the summer.

To try to discourage children using it, posters have been put up by police around parks, highlighting the potentially fatal effects. Possible side effects include fainting and brain damage.

Police first came across the canisters in July and made home visits to those believed to be using it and encouraging others to use it.

But the problem continues to remain a concern for the area as the town council found empty canisters last week.

Police are now asking parents to make sure their children are not using the drug.

PC Hazel Anderson said: “The message we wish to get across to parents is to make them aware these canisters are out there and get them to speak to the children.

“We also want to advise them the impact it can have on their health – ultimately it could potentially end in sudden death.

“At Corsham NPT we are aware of this due to more littering at local parks. We have designed a poster which has brief bullet points highlighting side effects.

“These have been displayed in the local park, so hopefully the message will get across to children in parks more readily.

“We’ve also informed the local secondary school and advised them they can incorporate it in their assemblies.”