A SCHOOLBOY who groped girl classmates during lessons was last night placed on the sex offenders' register after being found guilty of ten charges of indecent assault.

The 15-year-old, who cannot be identified for legal reasons, showed no emotion as magistrates convicted him at Darlington Youth Court yesterday.

The boy, who denied ten specimen charges of indecent assault on four girls aged 14 and 15, between September and November last year, had been accused of the same behaviour at a previous school, but the complaint was dropped, the court heard during the four-day hearing.

He was remanded on conditional bail and will be sentenced on September 16.

Darlington Borough Council last night defended its child protection guidelines in schools, saying that action was taken as soon as teachers at the new school were made aware of any fresh complaints.

But two of the four victims, who gave evidence by video-link earlier this week, claimed they had complained to teachers during French and science lessons, but nothing was done until a parent reported it to the deputy headteacher at a parents' evening.

Three of the victims were indecently assaulted during lessons, and one younger girl was groped by him on the school bus.

One of the victims, in a police video statement, said: "He is just a pervert. He can't keep his hands off anyone. I can't take it no more."

Another victim said he was a loner who did not mix well with his fellow classmates.

Last night, a council spokesman said: "The schools in Darlington have a procedure where, if an incident like this is reported, it is passed on to a nominated person. One teacher is responsible for dealing with these sort of reports.

"This is what happened immediately in this case. The teacher then completed a child protection report, which brings in the council's child protection team and the police.

"From the school's point of view, that is how it happened. Action was taken immediately the school was made aware. It is a pretty watertight system."

Last night, Sue Woolmore, the National Society for the Prevention of Cruelty to Children (NSPCC) public policy advisor for the North, said: "A higher proportion of sexual assaults are by young people than many people realise."

An NSPCC report, which has just been released, showed that almost half of sexual offenders cautioned by police in 1997 were aged between ten and 21.

The report says: "Research shows that 50 per cent of these children and young people have themselves experienced sexual victimisation.

"Children may also learn to behave this way through exposure to pornography or inappropriate sexual materials or behaviour."