Two Hong Kong activists who organised annual vigils to commemorate the 1989 Tiananmen Square crackdown have been found guilty of inciting others to subvert state power under the city's controversial national security law.

Lee Cheuk-yan, 69, and Chow Hang-tung, 41, face a maximum penalty of 10 years in jail after being convicted under the China-introduced law. Sentencing is expected at a later date.

A third defendant, Albert Ho, 74, pleaded guilty in January.

Lee and Chow "incited other persons to organise, plan, commit or participate in acts by unlawful means with a view to subverting the state power", according to a summary on Friday. Chow told the court in May the law itself was on trial.

Hong Kong used to be one of the only places in Chinese territory where people could gather to mark the deadly 1989 crackdown against pro-democracy protesters.

Authorities banned these gatherings in 2020, citing Covid-19 policies, but they have never resumed. This was also the year the national security law, which makes illegal a wider range of dissenting acts, officially came into force.

In mainland China, authorities have banned even oblique references to the 1989 crackdown.