Publishedduration1 hour agoshareSharenocloseShare pagelinkCopy linkAbout sharingimage copyrightReutersimage captionPolice from the National Security Department went to the university the day after the protest
Eight people have been arrested in Hong Kong after a protest at a university last month, as authorities continue to impose a tough new security law.
Three were detained on suspicion of inciting secession, which can carry a maximum sentence of life in prison.
In recent weeks activists have been jailed or detained under the new law, legislation human rights groups say amounts to "repression".
The US on Monday sanctioned 14 more Chinese officials over the clampdown.
The Treasury Department froze the assets and restricted the travel of 14 vice-chairs of the Standing Committee of the National People's Congress, which passed the National Security Law for Hong Kong.
In August, Hong Kong Chief Executive Carrie Lam was among 10 officials from the territory and the mainland put under such sanctions. She later said she had to keep "piles of cash" at home as she had no bank account.
- China's new law: Why is Hong Kong worried?
China and Hong Kong say the security law was needed to restore stability after chaotic pro-democracy protests but some Western nations, including the UK, say it has undermined the terms agreed ahead of the return of the territory's sovereignty from the UK to China in 1997.