A teenager from Bradford has been jailed for making a potential bomb.
Leeds Crown Court heard the 16-year-old had researched bomb-making and made a device that could have been a "viable C02 bomb".
The court was told how the device he made could, with the addition of gunpowder and a fuse, have been a credible threat.
He was convicted of making an explosive substance and three counts of having a document useful to someone committing or preparing an act of terrorism.
He was cleared of a more serious offence of making an explosive substance with intent.
The boy, who cannot be named, will be sentenced at the same court next month.