A teenage girl who called police after she saw someone with a knife has been praised.

The 13-year-old girl was with her friends in Watford when she noticed a group of teenage boys in the Harebreaks Recreation Ground on July 22.

One of them lifted up his top and the girl had seen that he had a knife in his waistband. She alerted police and officers attended the area.

The boy, 17, who is from Watford, was arrested on suspicion of having an article with a blade or point in a public place and taken to custody. He has been released under investigation while officers continue their enquiries.

The girl said she made the call because she had recently received the #LivesNotKnives presentation at school, learning how to reject knife and gang culture.

Yesterday (Monday) the girl and her mum visited Watford police station, where she was presented with a framed certificate of achievement and a £50 gift voucher as a thank you for making the right decision.

Chief Inspector Matt Phillips said: “It was an absolute pleasure to meet this young lady who displayed great courage when faced with a difficult situation.

“It’s so heartening to see that my team’s intensive preventative work is having a truly positive impact. We are committed to building relationships with young people to ensure they know we are here to help them.

“Our message to young people is loud and clear: you have a choice. Please don’t carry a knife.

“It is against the law and leaves you more vulnerable to being involved in violence. Make the right decision.”

Police have urged that if anyone has reason to believe someone is carrying a knife, do not approach them and instead talk to someone who can be trusted.