A controversial new hotline has been set up, encouraging people to report anyone taking part in the proposed week-long student boycott of classes starting on September 22.
"If your teachers or classmates are boycotting class, you can report them on this number: 2949 3193," said the anti-Occupy Central group Alliance for Peace and Democracy.
The alliance wants the public to report anyone participating in the boycott. The boycott is in response to Beijing's failure to offer Hong Kong greater electoral freedom.
Spokesman for the alliance Robert Chow Yung said the school's principal, its parent-teacher association and the Education Bureau would be informed if the hotline received multiple reports of plans for a boycott at a school.
"We are trying to protect students from being exploited. We are trying to help our society," he said.
But the hotline has already been widely criticised. Student group Scholarism said the alliance is creating "white terror" - a term associated with political repression. It said the alliance was violating students' privacy, adding the news will inspire more to boycott.
Meanwhile, the Professional Teachers' Union urged the alliance to drop the plan.
"We believe the education sector should be free from [outside] interference," the union said.
The Parents' Concern Group on National Education also said pupils should be free to decide whether they participate in class boycotts.
The hotline opened on Monday, but is yet to receive many reports. Instead, it has been bombarded by abusive calls.
"There are people calling non-stop saying things that are unrelated to the issue or yelling rude words. They are trying to block the line," said the alliance. "If these people continue to do so, we will report [it] to the police."