Parents are being urged to exercise caution in the face of a disturbing new game sweeping classrooms.

The game, which is being widely shared among youngsters on social media sites, sees children harming themselves.

Kids are undertaking the 'eraser challenge' - and mums and dads should be worried, experts say. The craze is also known as the ABC challenge, and reportedly started in the USA.

The 'challenge' encourages children of school age to recite the alphabet while rubbing pencil erasers on their skin until it's raw and peels away, causing red, burn-like marks and in some cases open wounds.

Children are then encouraged to post photographs of their damaged skin on social media, with the 'winner' being the person with the biggest wound.

Parents are being warned to look out for the marks on their children's skin after the game. Some children are sharing pictures of bandages or plasters on their wound with the hashtag #regret - but all too late.

One adult who posted a photograph of a young child's burn last year said: "This made me very sad, but satisfied as the boy told me how badly his arm hurt many days later and how he would never try anything like that again."

Schools are now sharing warnings to parents on their social media pages.