LONDON (AFP) - More than 60 per cent of school staff in Britain are aware of 13- to 16-year-olds sharing sexual material online, and pupils as young as seven have been caught "sexting", a study said on Friday (March 25).

The report from teaching union NASUWT found that 63 per cent of teachers were aware of 14-year-olds sexting, while 45 per cent said they knew of 13-year-olds sharing material of a sexual nature.

A small amount of teachers said seven-, eight-, and nine-year-olds were engaged in such behaviour, and a quarter of respondents said they were aware of 11-year-olds sexting.

Around half of all teachers said they knew of pupils using social media to send sexist and bullying messages to other students, and a similar number were aware of racist messages.

Half of them had suffered online abuse and negative comments, including false accusations of paedophilia.

Almost a third of teachers reported seeing online photos or videos of themselves taken without consent.

"Over the three years the NASUWT has been running this survey the situation has deteriorate," said the union's general secretary Chris Keates.

"Online abuse has a devastating impact on teachers' and pupils' lives and yet no serious action is taken by government to ensure that schools are responding appropriately to this abuse.

"The level of abuse that teachers are suffering at the hands of parents online is simply unacceptable."

Examples of abuse included a fake Twitter account describing the teacher as a wife beater and parents threatening to "knock out" teachers.

The Department for Education stressed that teachers "have a right to feel safe" at work.

"We want to make sure young people are aware of the risks and dangers - including sending inappropriate images," said the department.

"The law is also crystal clear that where teachers find indecent images of children they must report this to the police."