Campaigners have warned that the record numbers of people being stopped and searched in Scotland could alienate the young and breach their human rights.

More than 23,000 children aged under 15 have been dealt with by officers using the powers since the new single police force was set up north of the Border in April.

The official figures emerged as Scotland's human rights commissioner, Professor Alan Miller, warned against police targeting stop and searches which are taking place in record numbers.

The Herald reported yesterday there are rising concerns the practice is target-driven, which is denied by the police

Professor Miller said: "This is a dramatic escalation of the use of stop-search powers. Either we are all acting more suspiciously than ever before or there is a definite change in practice being driven across Scotland.

"If it is the case that they are acting on grounds of reasonable suspicion that is fine, but if it is driven by targets, it is likely to be breaching people's right to respect for their private life."

Police Scotland has used stop-search powers on a massive scale since it took over policing. It included a doubling of the number of people being dealt with in Edinburgh.

The force says the overall increase in the past year is just 6% nationally but this is part of an upward trend over time.

The total is a far higher proportion of the public than is being stop searched by forces in England and Wales where the legislation is different but the population is more than 10 times higher than Scotland's 5.2 million.

Across Scotland, officers stopped and searched 186,463 members of the public in the first three months of Police Scotland's existence. Senior police say stop and search is just one of a number of policing tactics used to tackle serious violent crime and keep people safe, and that its use should always be proportionate and intelligence-led.

Most searches were on young men. More than 23,000 stop searches (12.6%) were carried out on children under 15. More than 80% of those searched were male; 55% were aged between 16 and 29; and 97% were white.

Last year across Strathclyde there were more than 612,000 stop searches, although senior police say this led to a record performance with a 50% reduction in violent crime since 2007. The numbers have increased considerably. In 2010/11 Strathclyde conducted 391,000 stop searches and in 2011/12 there were 493,000.

People can be stopped and searched if the police have probable suspicion that an individual is engaged in specific kinds of criminal activity. However, earlier this month frontline officers in Scotland were told to prioritise stop searches.

An email sent to approximately 1800 officers in Greater Glasgow by an inspector on August 7 told them to use overtime "solely for the purpose of targeting stop searches within GD Sub-Division" and that "NIL returns are not acceptable under any circumstances".

Following complaints from officers, a clarification was sent the following day explaining that they have to be ethical and that "activity has to be focused on the right people at the right places". Police said this was a "genuine misunderstanding and misleading in its interpretation of the approach".

Tam Baillie, Scotland's Commissioner for Children and Young People, said: "While we all welcome a reduction in crime figures, we need to carefully consider the consequences of an increase in stop and search. There is a risk of reinforcing some young people's sense of alienation and separation from mainstream society.

"We know from research, the importance of young people having a positive sense of identity that is respected within their home environment and local area. Young people have a right to assemble and socialise with their friends on the streets and in public spaces, without feeling they are being treated as criminals. I would hope that the police are also actively engaging in a positive way with young people - particularly in so-called crime hotspots."

Yesterday, Police Scotland Chief Constable Sir Stephen House and Deputy Chief Constable Rose Fitzpatrick told the Scottish Police Authority that the searches are not driven by targets.

Sir Stephen said: "I believe strongly in this tactic if it is done properly, with integrity, fairness and respect." He said he speaks regularly to school groups and that what young people want is "politeness" and "an explanation".

Just 19 complaints have been made about stop searches this year and one in five searches was positive as compared to less than 10% in England, where the practice has been regularly criticised for being racist.

Ms Fitzpatrick said it is a significant power which comes with significant responsibility.

The report from Sir Stephen states the tactic should be lawful, proportionate, intelligence-led and respectful. "There are no individual officer targets for stop-and-search activity."

Scottish Conservative chief whip John Lamont said: "Stop and searches are an essential way of catching people with weapons or drugs."