Hong Kong’s new national security education curriculum will force teachers to warn primary students as young as six years old against “subversion” and to throw out library books considered dangerous to the Chinese state.

Hong Kong’s education bureau released the guidelines on Thursday, which will also impact expat students at international schools. The department said that while they accepted these schools’ curricula was different, teachers would be expected to ensure students “acquire a correct and objective understanding” of principles in line with Beijing’s tough national security law introduced last year.

Authorities have come under pressure to make changes to the education system after pro-Beijing politicians and state media blamed teachers and the curriculum for the months-long anti-government protests in 2019, in which thousands of students took part.

The education overhaul shows that China’s crackdown on the former British colony has reached beyond jailing opposition leaders to reforming Hong Kong society to bring it more in line with the mainland.

The security law was a response to the pro-democracy protests, one of the biggest challenges to central authorities on Chinese soil in decades. Beijing’s supporters say that promoting patriotism in students will prevent future unrest.

“As far as prevention and education are concerned, all schools (including primary schools, secondary schools and kindergartens) have a significant role to play,” the city’s education bureau said in a statement.

The education bureau detailed specific measures for local schools, forcing teachers to warn primary and secondary students against “subversion” and “foreign interference”, as outlined in the new security law. Schools should stop students and teachers from participating in political activities and make reports to the police when necessary.

The bureau advised teachers and principals to closely inspect noticeboards in classrooms and to clear out library books that “endanger national security”.

Tin Fong-Chak, a vice-president of the Hong Kong Professional Teachers Union, said the guidelines were “extremely meticulous” and would control everything that happened in schools.

“The government basically does not trust schools,” Mr Tin said. “These measures will destroy the teacher-student relationship.”

Schools are also expected to set up a working group and submit proposals and reports to the bureau on the implementation of the changes from August.

There are 52 international schools in Hong Kong that cater to expatriate and local students, especially those looking to study abroad. The territory is home to 587 primary and 504 secondary schools.

Teachers of subjects such as geography and biology will also need to incorporate lessons about national security into the topics taught in class. The resources provided by the bureau suggested that biology students should, for example, study how the local and mainland Chinese government protected the country during the pandemic.

The city is also in the process of making changes to a secondary school subject called liberal studies, which will now focus on fostering patriotism among students.