Hong Kong’s new security law is “unambiguous” about what counts as unlawful seditious acts, the city’s government has said.

Chu Kai-pong is first person to be convicted under Article 23, the China-ruled city’s tough new national security law.

A Hong Kong court sentenced a man to 14 months in prison for wearing a T-shirt with protest slogans, marking the city’s first use of a new national security law to punish people accused of endangering the Chinese state.