US-funded Radio Free Asia (RFA) has closed its Hong Kong bureau over safety concerns for its staff in the wake of a new national security law known as Article 23.

“Actions by Hong Kong authorities, including referring to RFA as a ‘foreign force’, raise serious questions about our ability to operate in safety with the enactment of Article 23,” its president, Bay Fang, said in a statement on Friday.

The new law comes with stiffer punishments from several years up to life in jail for crimes including treason, sedition, state secrets, espionage and external interference.