The head of the Centre for Suicide Research and Prevention at the University of Hong Kong (HKU) on Saturday said a new three-tier emergency system will do little to prevent student suicides in the long run.

Professor Paul Yip made the comment a day after the government announced the launch of the mechanism, which helps schools identify pupils with a higher suicide risk early and give them professional support.

Yip said the two-month system may not address the crux of the issue, adding that it's more important to build better ties between teachers and students.

"For those people who are not well, if you can provide an early treatment for them, it is important. But because it [the system] only lasts for two months, I think the impact itself will be expected to be quite limited," he told reporters after attending a radio programme.

"But the more important thing, I think, is the restoration of the relationship between the students and the teachers and the students among themselves. They are very important because these are the important social support systems for our students."

Speaking on the same radio programme, HKU professor and paediatrician Patrick Ip said the Covid pandemic has taken a toll on students' mental health, adding that more support should be given to parents and teachers as well.

"During the Covid pandemic, we believe because of the stopping of the physical schooling for such a long period of time, which is actually one of the longest periods in the world, actually have stopped children from better communication with their peers and also with their teachers and social workers," he told reporters.

"When they are now resuming normal schooling and normal activities, the focus should not be over-emphasised on the school academic work, but should be a more encouraging and more positive environment."