Hongkongers who repost, and agree with, overseas criticism of the city’s new, domestic national security law could breach the legislation if they are found to have been inciting hatred against the authorities, justice minister Paul Lam has said.

The Article 23 legislation, which came into force on Saturday, includes penalties of up to life imprisonment for five categories of crime including treason, insurrection, espionage, sabotage and external interference.

It also expands the British colonial-era offence of “sedition” to include inciting hatred against China’s Communist party leadership.

Hong Kong security chief Chris Tang said that additional evidence such as “what you keep at home and what other acts you have done” would have to be collected to facilitate prosecution.

“As I often said, if you breached the law, I will definitely find evidence against you,” Tang said.