Almost 3,000 were carried out on 8 to 17 year-olds between 2018 and the middle of last year - in schools, police vehicles and even takeaways.
Children's commissioner Dame Rachel de Souza says young people are 'being failed' - while charities say the searches as 'racist and traumatising'.
Twickenham Lib Dem MP Munira Wilson says the report is “utterly shocking”.
She says she demanded ministers review guidance and speak to every police force a year ago, and asks “what have they been doing?”.