HONG KONG - Hong Kong's education chief on Thursday strongly condemned the latest rhetoric glamorizing terrorism and violent crimes from the University of Hong Kong's Students' Union, calling for action to protect local students from the "poison" of immorality.

In a letter to all principals and teachers in the special administrative region, Secretary for Education Kevin Yeung Yun-hung warned of the baneful influence created by attempts to downplay or whitewash the violence and terrorism in a series of criminal cases, including one in which a gang of several youngsters allegedly attempted to detonate homemade bombs in public.

He condemned the Students' Union for paying tribute to a "lone wolf" terrorist who stabbed a police officer in Causeway Bay on July 1 before killing himself. In a meeting resolution of the student union's council, the students said they "appreciate the sacrifice" of the assailant. One of the student representatives, Anthony Yung Chung-hei, said he "saluted" the attacker.

The radical students involved should be "harshly denounced" as they "failed to distinguish right from wrong", he said.

The city's Security Bureau joined the authorities' chorus of condemnation. "These students, who have received higher education, have failed the expectations of their parents, society and the university. They should be ashamed of their behavior," the Security Bureau said in a statement. The case highlighted the importance of national security education and the SAR government's supervision of education institutions, the statement continued.

The University of Hong Kong, in a separate statement, said that "the portrayal of the stabbing of a police officer and the suicide of the attacker as 'sacrifice' sent a totally wrong message to society." It then condemned all forms of violence and opposes any speech or acts that promote and justify violence.

The Hong Kong Federation of Education Workers, Hong Kong's second-largest teachers union, urged an end to all attempts to glorify violence, saying it would promote hatred among young students.

Earlier this week, six secondary school students were arrested over an alleged plot to set off homemade bombs in courts, tunnels, and trash cans. Their patron and accomplices include at least two educators from a secondary school and a local university.

Yeung also said that the recent illegal incidents have been a wake-up call for society, as it shows that criminals and those with ulterior motives are trying every method to influence and stir up young people, erode their values and lead them astray.

Yeung urged the educators in the city to remain professional and vigilant, and to ensure the students be fully aware of the importance of abiding by the law, and being instilled with correct values and capable of emotional management.