A teenager has been jailed for two years and eight months after being caught with petrol bombs during a protest in Tuen Mun last year.
Student Chan Kwok-ching, 17, was carrying three petrol bombs and substances said to be able to make another 20 or so when he was stopped by police on November 10.
He pleaded guilty at the District Court to possessing items with the intent to destroy or damage property.
The teenager also had three Octopus Cards on him, which the prosecution said were to hide details of his travels around the city.
The defence pleaded for leniency given the student's young age and asked for him to be sent to a detention centre for rehabilitation.
But judge Amanda Woodcock said the teenager's behaviour made him a criminal, not a protester, and he can't be allowed to use his youth to his advantage.
She said Chan had acted with the utmost contempt and disdain for law and order, rejecting his claim to have acted on impulse and out of ignorance.
The judge said he had crossed the line that protects public order, beyond which "society is prone to descend into anarchy".
She also ordered the teenager to see a psychologist regularly while serving his prison term, to learn to think about the consequences of his actions and how to make good decisions.