Teachers have demanded websites such as Youtube and Rate My Teacher should be closed down to protect schoolchildren and staff from online bullying.

Cyber-bullying is increasing as a result of such sites and making victims vulnerable 24 hours a day, teachers told delegates at the annual conference of the Professional Association of Teachers.

Speaking at the conference, Kirsti Paterson, teacher and member of the Highland & Western Isles Federation SEC Committee, said that bullying had gone from the playground and into the digital space through the “misuse of mobile phones and websites". As a result both teachers and children were being targetted bullies.

She gave an example of when a picture of a staff member was taken during a class lesson and posted on a website with the caption “you are dead”.

Catriona Tait, a primary teacher from Dundee, pointed out at the conference that one in four pupils had experienced cyber-bullying at some time. She said this “was worse than face-to-face bullying” as it gave “no sanctuary to hide from the endless threats and torment.”

Rate my teacher, a website that allows pupils to post comments about their teachers, was also criticised by Ms Paterson. She said it was being used by pupils to make hurtful and offensive comments about school staff.

Both teachers said that the short-term solution to the cyber bullying problem would be the “closure of these sites.” However, the National Union of Teachers (NUT) and children’s charity NCH disagreed with this describing it as “over the top."

John Carr, technology advisor at the NCH, told Computeractive: “Sites such as Youtube are wonderful places for people of all ages and give people a good way to communicate with each other.

“Yes there are some issues with them but closing them down would be like throwing the baby out with the bath water. It’s just not the answer.”

Carr advised teachers and schools to work on disciplinary issues and educate children on the effects that posting harmful videos and messages could have.

“Children need to know that just by downloading a video with offensive content that they are breaking rules and harming an individual,” he added.

The NUT said “improved control from owners of the sites” would be a better step to ensure they were safer.

Youtube said in a statement that it had joined the Government's bullying task force, and would work closely with teachers unions and others to ensure that it improved its site safety.