Hong Kong authorities have hit out at The Washington Post for making “groundless allegations” about amendments to the city’s home-grown national security law in an editorial piece, while stressing that foreign businesses have no cause for concern.

The rebuttal issued by a government spokesman late on Saturday night followed a commentary from the American newspaper, titled “Hong Kong’s nightmare gets darker”.

The piece described the introduction of a new mechanism under the Safeguarding National Security Ordinance, which allows the city leader to classify legal cases as national security ones, as “repressive”.

In the statement, the government said the subsidiary legislation gazetted earlier in the week only aimed to clarify “other offences endangering national security” under the relevant legislation and to offer more certainty in their implementation.

“The Procedural Matters Regulation will in no way infringe any legitimate right of a defendant. Hong Kong is a place underpinned by the rule of law,” it said.

“The guilt or innocence of a defendant remains a matter to be adjudicated by the court independently and in accordance with the law. The court will, as always, ensure a defendant’s right to a fair trial.”

Authorities gazetted the Safeguarding National Security (Procedural Matters) Regulation on Tuesday, which stipulates that the chief executive can issue a certificate to classify any case as an alleged national security offence.