HONG KONG, Oct. 23 (Xinhua) -- Multiple police officers associations in China's Hong Kong on Wednesday urged Rocky Tuan, president of the Chinese University of Hong Kong, not to bring politics to campus and expressed concerns that Tuan's move will lead to more colleges affected by political conflict.

Tuan accused Hong Kong police of using improper violence against students in an open letter, shunning violent acts of those students. He said the university reached out to more than 30 arrested students, most of whom claimed to be treated unreasonably.

Tuan asked the police to make clarification, and said he would write to Chief Executive of the Hong Kong Special Administrative Region Carrie Lam.

The officers groups said that they regretted that Tuan did not mention the serious crimes that the students were suspected of committing but shouted at the top of his voice to demand investigation and denounce the police.

Students are easily incited or exploited to conduct illegal violent acts and the universities have the responsibility to guide students to think independently and distinguish right from wrong, the groups said.

The groups urged Tuan to encourage the students who break the law to bear the legal responsibilities and instead of shielding them from the legal responsibilities, impose reasonable punishment on them as the president.

Some Hong Kong students recently went to extreme by forcing their universities to support their political demands and condemn the police in hopes of justifying their illegal activities, the groups said, noting that Tuan's move set a very bad precedent that will arouse those students to increase pressure on their universities.

The associations that co-signed the letter were Superintendents' Association of Hong Kong, Hong Kong Police Inspectors' Association, Overseas Inspectors' Association, and Junior Police Officers' Association.