National security police on Wednesday said they arrested one more person on suspicion of "offences in connection with seditious intention" under the Basic Law Article 23 national security legislation.

Six people, including the former vice-chairwoman of the now-defunct Hong Kong Alliance, Chow Hang-tung, were arrested on Tuesday and linked to seditious posts published on social media ahead of what authorities described as a "sensitive date".

It is understood that a 53-year-old woman arrested on Wednesday is the wife of one of those taken into custody the day before.

Officers are not ruling out further arrests.