Police said more than 200 uniformed and plainclothes police were deployed to search the publication’s office in the Kwun Tong district.

An AFP reporter saw Stand News editor-in-chief Patrick Lam being led into the news outlet’s office building in handcuffs.

Stand News is the second Hong Kong media company targeted by national security police following Apple Daily, which closed in June after authorities froze its assets under a national security law imposed by Beijing to curb dissent.

Local pop star Denise Ho, who served on the board of Stand News but resigned in November, was also arrested, according to her Facebook page.

Shortly before dawn, Stand News broadcast live on Facebook that national security police were outside the door of deputy assignment editor Ronson Chan.

In the brief video, officers told Chan they had a court warrant to investigate charges of “conspiracy to publish seditious publication”, and that Chan must stop filming.

Chan, who is also chair of the Hong Kong Journalists Association, was reportedly asked to assist police in their investigation but not among those arrested.

Others arrested were barrister and former pro-democracy lawmaker Margaret Ng and Stand News former editor-in-chief Chung Pui-kuen, according to local media.