A 16-year-old boy stopped by counter-terrorism officers at Heathrow Airport was found to have downloaded Al Qaida manuals containing instructions on how to build explosives. Yusuf Shah, from Ilford on the Essex border, was stopped by counter-terrorism officers at the airport in January 2024. Police seized his mobile phone at the terminal and later searched his family home, uncovering a haul of computers and USB storage devices. Detectives discovered the teenager had been active on social media discussing religion since the age of 13. But by the end of 2022, he began expressing support for terrorist groups including Al Qaida and Tehrik-e-Taliban. Police seized his mobile phone at the terminal and later searched his family home, uncovering a haul of computers and USB storage devices. Detectives discovered the teenager had been active on social media discussing religion since the age of 13. But by the end of 2022, he began expressing support for terrorist groups including Al Qaida and Tehrik-e-Taliban. He then began offering his technical computer knowledge to these groups, including advice on how to avoid detection when making cryptocurrency payments. An analysis of his phone showed he had downloaded online magazines containing instructions on how to make explosives and weapon guides. In March 2024, an individual on the messaging app Telegram approached Shah to help produce a cybersecurity guide for a senior official in the Tehrik-e-Taliban. Shah quickly drafted a document titled "A Guide on Cybersecurity" and sent it directly to the terrorist group to help them conduct their activities in secret. Commander Helen Flanagan, head of Counter Terrorism Policing London, warned that this case reflects a worrying trend of children being radicalised online. “Even at the age of just 16, Shah had enough knowledge of the online world to be able to provide practical advice to terrorist groups on how to make anonymous cryptocurrency payments," she said. "It is vital that parents and carers are aware of what children are doing on the internet, especially if they are accessing social media platforms. "I would implore you to have conversations, to be inquisitive about what your children are doing online, and if you have any concerns, then there is help available to you via the ACT Early website." Following a five-week trial at Kingston Crown Court, Shah was convicted of funding arrangements, providing terrorist training, and collecting terrorist materials. The 18-year-old has been remanded in custody and is due to be sentenced at Kingston Crown Court on September 16.