A new report found that one in three girls wearing school uniforms in the United Kingdom has been sexually harassed in public, while two-thirds say they’ve received unwanted sexual attention.

“It’s simply not acceptable that girls as young as 12 are being wolf-whistled at in public, touched against their will, stared at or even followed,” Tanya Barron, chief executive of Plan International UK, the organization that commissioned the report, told BBC.

Barron added that it was “shocking and deeply concerning” for girls of school age to be sexually harassed.

The report, which was based on a survey of 1,000 teenagers and young women between the ages of 14 to 21, found street harassment to be ubiquitous. Often starting as early as primary school, girls in their uniforms experience unwanted sexual attention, the report said. The girls described feeling “sexualized and fetishized” by “older men targeting school girls” because of the outfits required of nearly all Britain’s students.

More than a third of the girls reported being touched, groped or grabbed without their consent. One-quarter said they were filmed or photographed without permission, including some who noticed strangers trying to take pictures up their school skirts.

“I’ve never experienced harassment like I did then,” Ffion, 25, told the surveyors. “Men would ask if they could take a picture with me in my uniform. It was awful. Before that I used to be walking home, and I was so scared walking home.”

But many girls also dismissed the street harassment as “all part of growing up.”

“These experiences are widely trivialized, creating a culture of acceptance and normalization,” the report says.

Plan International is calling on bystanders to intervene, and requesting the government acknowledge street harassment as a kind of “gender-based violence.”

“This disgraceful behavior needs to be called out and stopped,” said Barron.

Get The Brief. Sign up to receive the top stories you need to know right now. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Contact us at letters@time.com.