New figures show the number of under-16s charged with possession or supply has gone up by 13% since 2002.

The statistics from seven Scots police forces, including Strathclyde, show several 13-year-olds have been found dealing heroin, while children as young as 10 have been caught with cannabis.

The rise in cannabis offences has led to calls for its downgrading to be reversed.

In January 2004, David Blunkett, as Home Secretary, reclassified cannabis from Class B to Class C.

The Government said the move would allow police to concentrate on cracking down on hard drugs.

But opponents say the reclassification was like a green light for thousands of people who previously would not have used cannabis, which has been found to trigger mental health problems.

Professor Neil McKeganey, from the Centre of Drug Misuse at Glasgow University, said: “The reclassification was a bad idea. It conveyed a message to young people that the drug wasn’t important enough to be concerned about.

“Now cannabis isn’t even seen as an illegal drug by many young people.” Annabel Goldie, home affairs spokeswoman for the Scottish Tories, said: “The reclassification was absolute madness and and must be reversed. “A simple zero-tolerance approach has to be the starting point if we are ever going to win the war against drugs.”

Stewart Stevenson, the SNP’s deputy justice spokesman, said: “We must be unambiguous in our opposition to this and all other drugs.” He added: “There are no risk-free drugs.”

Across Scotland, the number of youngsters aged 16 and under arrested for possession and intent to supply cannabis rose from 1063 to 1204. In Strathclyde, it rose from 672 to 695. THE downgrading of cannabis was today blamed for a rise in Scots children arrested for drugs offences.

New figures show the number of under-16s charged with possession or supply has gone up by 13% since 2002.

The rise in cannabis offences has led to calls for its downgrading to be reversed.