A NEWPORT youth aged 13 was locked up for two and a half years for robbery.

Another 13-year-old boy was given a six-month training and detention order for affray.

The pair are the youngest offenders in crime figures that show sharp rises in convictions for violence, robbery and car theft among ten- to 17-year- olds in the last year.

Car theft went up by 28% to 91 incidents, while robbery leaped 56% to 28 cases. There were 132 violence-related offences - a rise of 16%. But the total number of incidents - 1,196 - was similar to last year's 1,155.

Andrew Wallsgrove, youth offending team manager, said that only three youngsters were given custodial sentences of over two years, showing that "very serious offending is very much the exception".

He told Newport council cabinet the Argus crackdown on car crime may have helped boost conviction rates for vehicle offences.

The youth offending team tries to stop youngsters passing through the court system re-offending.

In 2003 the Newport team was consistently among the top quarter of youth justice teams in England and Wales.

But councillors were angry that Mr Wallsgrove said youngsters were at risk of offending because they "have nothing to do".

Councillor Glyn Jarvis, cabinet member for culture and leisure, said: "There's a lot for them to do. A tremendous amount of money has been spent on facilities.

"It's a hardcore of offenders that needs to be sorted out." Councillor Bob Bright, cabinet member for community safety, said: "This hardcore of offenders are committing 60% to 70% of the crimes. Their anti-social behaviour causes fear and despondency."

Mr Walls-grove said his team did not deal with antisocial behaviour orders, but were taking steps to address the problem.

Chris Free-gard, managing director of the council, said: "Anti-social behaviour in Newport has dropped because of our approach. We use wardens, police community safety officers and there has been a refocus from the police."