File photo: Reuters

London - ChildLine has received hundreds of calls from teenage girls under pressure to send boys sexual images of themselves in a phenomenon known as “sexting”.

Many say they have already sent pictures and videos but regret it “ in many cases because the images have been shared between the boys’ friends or even put up on the internet.

The pictures are usually taken on mobile phones and then texted or emailed to boys.

ChildLine said it carried out 274 counselling sessions about sexting in the year 2011/12.

Many girls who take part in the practice have told ChildLine that they have ended up with depression or mental health problems, because they are humiliated by the sharing of the images. Others regret taking part because they do not think they are ready.

The NSPCC warns that girls are being pressurised into copying what happens in videos they see online, and then “sext” the images to boys.

They say the influence of internet porn means that boys are increasingly seeing girls merely as sex objects - putting them under pressure to perform for them.

Esther Rantzen, founder of ChildLine, said: “Young people need to know that ‘sexting’ and being abused are not a normal part of growing up and that they have the right to say no.”

A study by parent advice charity Family Lives earlier this year found that girls as young as 11 are taking part in intimate webcam sessions on social networking sites.

And Peter Davies of the Child Exploitation and Online Protection centre, warned that the phenomenon of sexting was now so widespread that children as young as five need to be taught about the dangers in school.

“The moment a child becomes the subject of the education system, that’s when you should start,” he told MPs on the education select committee.

“We used to extend our education packages down to ten, they are now down to about eight.

“We are realising we may need to pitch them at ages below that because this is not something that kids do when they are at home under the natural surveillance of their family - the phone is in their pocket and with them all the time.”