The bureau warned that if the two secondary teachers commit another offense, their teacher registration could be revoked.

The punishment came after former chief executive Leung Chun-ying urged the school to dismiss the two teachers. His comment was echoed by an article in the People’s Daily, the official Communist Party newspaper, which urged the Education Bureau to handle the case seriously and to ensure a peaceful environment at the school.

The bureau said it had handled 59 complaints related to anti-extradition bill protesters, Ming Pao Daily reported.

Five of those looked at were classed as unsubstantiated, while two had merit, which led to the bureau issuing letters of condemnation. The rest of the cases are still being investigated.

One letter is believed to have been sent to Alvin Tai Kin-fai, assistant principal of the Hong Kong Chinese Christian Churches Union Logos Academy.

Tai is alleged to have written on Facebook that he wishes “the children of policemen who used violence die before they reach the age of seven, or die before 20 years old should they now be seven or older.”

It is understood that the school removed Tai as its assistant principal and gave him other work.

Meanwhile, Colin Lai, a liberal studies teacher at Sacred Heart Canossian College, is said to be another teacher who received a ‘please explain’ letter. Lai allegedly updated his profile picture on social media to include the slogan “black cops’ families all die” in response to clashes between protesters and police on June 12.

Lai later apologized and resigned as he is also the chairman of the Hong Kong Examination and Assessment Authority’s Committee on Liberal Studies.

‘Cockroaches’

Meanwhile, another case related to a post on social media allegedly written by an assistant principal of Man Kiu College with the surname Song. It said: “I don’t welcome those ‘cockroaches’ as my school students”. However, the bureau conducted an inquiry but classed that matter as unsubstantiated.

“Cockroaches” is the term used by police or pro-Beijing supporters to describe protesters.

The college explained that Ms Song did not post such a comment and believed that her account was hacked.

Fung Wai-wah, president of the Hong Kong Professional Teachers’ Union, the largest teachers’ union in the city, said the two teachers said to have spread hate speech about police had apologized and the letters of condemnation that they received was a serious punishment.

Fung urged the bureau to disclose the criteria when they assess complaints to ensure it is fair and not affected by any political stance.

But Wong Kam-leung, chairman of pro-government Hong Kong Federation of Education Workers, said the punishment given to the teachers was too lenient. Wong believed the public might not accept such lenient treatment as they have higher expectations about the conduct of teachers.

623 complaints about police

Meanwhile, officials with the Independent Police Complaints Council (IPCC), which held an open meeting on Tuesday, said 2,823 people had contacted the Complaints Against Police Office to file 623 complaints about officers’ behavior during the protests, which began in June.

Around 220 complaints were filed by alleged victims. Most relate to allegations of misconduct and neglect of duty.

At the meeting, some IPCC members said they were concerned that officers could not be identified as some riot police and special tactical squads failed to show their warrant cards or identification numbers on their uniforms.

The force said recently that officers will display their identification on their helmets.

The IPCC’s chairman, lawyer Anthony Neoh SC, said there were no complaints about officers failing to display identifying numbers on their uniform.

He and the head of the Complaints Against Police Office, chief superintendent Tammy Mak Wai-man, said police could generally locate the officer if complainants were able to provide the time and location of the incident.