A 15-year-old boy has appeared in court accused of planning a so-called Islamic State-inspired terror attack after allegedly researching the Isle of Wight Festival as a potential target.

The teenager had a knife in his rucksack when he was arrested by counter-terrorism police last Monday following a tip-off from the FBI that he was planning to attack a non-believer who he thought had insulted Islam, Westminster Magistrates’ Court heard.

The boy, from Cowes on the Isle of Wight, appeared in the dock on Monday to deny a charge of preparation of terrorist acts under Section 5 of the Terrorism Act 2006.

Prosecutors say he researched the music festival, held between June 16 and 19 on the Island, which was attended by around 90,000 people and featured acts including Lewis Capaldi and Kasabian.

The youngster, who cannot legally be identified because of his age, is said to have developed an interest in extreme Islam and supported Isis ideology.

As well as carrying out online research into a location to commit an attack, the youth is said to have looked at weapons, including firearms, vehicles and a stab vest.

He is also said to have obtained a knife and written notes, including an alleged martyrdom note entitled To My Family.

He was arrested by officers from Counter Terrorism Policing South East (CTPSE) with help from Hampshire Constabulary on Monday July 11 and charged on Sunday.

The boy, wearing a grey sweatshirt, dark trousers and black trainers, stood in the well of the court to confirm his name, date of birth and address, before pleading not guilty.

Deputy Chief Magistrate Tan Ikram remanded him into youth detention accommodation ahead of his next appearance at the Old Bailey on August 19.