It has emerged that a suspected paedophile has been attempting to groom UK schoolchildren on social networking site Facebook by posing as their new classmate.
Warning letters have been sent to hundreds of worried parents in Cambridgeshire after police discovered the method the predator was using.
The man created a series of fake Facebook profiles to issue "friend requests" to children from two secondary schools in Cambridgeshire, and he even encouraged his victims to use their webcams while emailing him.
Headteacher Catherine Jenkinson-Dix, of City of Ely Community College, has written a warning letter to parents urging them to take "extra precautions".
"We have been informed by the police that a man has been posing as a child on social networking sites such as Facebook," the Daily Mail quoted her as having written in the letter.
"The man has targeted children from two local secondary schools, trying to befriend them by saying that he is starting at the school in January and is looking to make new friends.
"He has tried to gain personal information and has got some children to use their webcams.
"So far, the police have traced three bogus names. However, they may be more.
"I am sure that you will discuss with your child the dangers of using the Internet and ensure that they do not put themselves in a vulnerable position, and that they take extra precautions now that they are home over the festive season," she stated.
Detectives investigating the suspected Facebook paedophile believe he has used profile names Harry Clark, Mike Smith and Elton Steinbeck, but fear he has other aliases.
A Cambridgeshire Constabulary spokesman has warned children not to accept "friend requests" from strangers.
Facebook users are advised to download a Panic Button application, which allows them to contact the Child Exploitation and Online Protection Centre (CEOP)