Image copyright Suffok Police Image caption PAVA replaced CS spray and is said to be safer and more effective than the original

Children as young as four have been mistakenly sprayed with "hot chilli" by Gwent Police.

On Wednesday, officers visited Ysgol Gymraeg Gilfach Fargoed, in Bargoed, Caerphilly county, and gave a lesson on equipment used by the force.

But instead of demonstrating a mock PAVA spray, which replaced CS spray, officers discharged a real canister.

The spray, used on eight pupils aged four and five, causes the eyes to close and is extremely painful.

None of them needed hospital treatment, said the force, which has apologised for the error.

"Parents were contacted by a senior officer to explain what happened, discuss any concerns and offer our sincere apologies," a spokesman said.

"Medical treatment wasn't required on the day, however, parents were advised to seek medical attention if they had any concerns.

"Further enquiries into the error are now being undertaken and, as a result of yesterday's incident, school liaison officers will no longer be taking any demonstration (mock) PAVA spray into schools."

PAVA (pelargonic acid vanillylamide) is a synthetic version of pepper spray. It replaced CS spray because it was said to be safer and more effective when restraining suspects.

It is claimed it is less likely to contaminate officers or bystanders.