Eight people in Hong Kong have been arrested, including three on suspicion of violating a national security law, over a protest at a university last month, police said on Monday, as the government intensifies a crackdown on pro-democracy activists.

In recent weeks, Hong Kong has dismissed opposition lawmakers, jailed high-profile activists including Joshua Wong, and denied bail to media tycoon Jimmy Lai, 73, an ardent critic of Beijing who owns the anti-government tabloid, Apple Daily.

Police said eight males aged between 16 and 34 were arrested for illegal assembly at the Chinese University of Hong Kong (CUHK) and three of them — who were not students at the university — were also arrested on suspicion of inciting secession.