The boy was arrested under the Terrorism Act as part of a pre-planned operation.
The 17-year-old from Essex, who cannot be named due to his age, has been charged with six terrorism offences following an investigation led by Counter Terrorism Policing North East, supported by Eastern Region Special Operations Unit (ERSOU) and Essex Police.
On the morning of Tuesday 29th December, the boy was arrested and detained under the Terrorism Act, as part of a pre-planned, intelligence led operation.
Two residential properties in Chelmsford and Brentwood were also searched in connection with the arrest.
On Wednesday 30th December, Detectives requested a warrant of further detention, which was approved by the court, giving officers extra time to hold and question him.
As reported by BBC News, the boy is accused of preparing for a terrorist attack by drawing up plans for a storage bunker, providing information for the manufacture of firearms by a 3D printer, and transferring money to another person for materials to manufacture them.
It is alleged that his intended target was another person.
On Sunday 3rd January, the boy was charged with the following offences:
1 offence of Engaging in the preparation of an act of terrorism, contrary to Section 5 of the Terrorism Act 2006
1 offence of Disseminating a terrorist publication, contrary to Section 2 (1) of the Terrorism Act 2006.
4 offences of Possessing material likely to be useful to a person committing or preparing an act of terrorism, contrary to Section 58 of the Terrorism Act 2006.
He appeared before Westminster Magistrates Court via video link on Monday 4th January and was remanded in custody to appear at the Old Bailey on 22nd January.