(Bloomberg) -- Nearly 1,000 teachers have left Hong Kong in the past school year in the wake of a China-drafted national security law and strict Covid-zero policies.

Between August last year and June 2021, 987 secondary school teachers departed, almost double the previous two years combined, according to a survey by the Hong Kong Association of the Heads of Secondary Schools. 

Reasons cited for the brain drain were changes in “social atmosphere” and education policy, as well as challenges related to Covid-19, according to the poll published Wednesday of international and public schools. Most of the 140 principals surveyed thought the exodus would continue.

“We are much concerned about whether there would be enough trained teachers to fill the vacancies,” the association said in the report. “In recent years, many principals have expressed difficulties in staff recruitment.”

Hong Kong’s population is falling at a record pace, with 89,200 residents leaving in the year ending June, after the city last year recorded the biggest drop in at least six decades. That exodus comes as the security law is used to crack down on freedoms and strict pandemic rules impose 21-day hotel quarantines for fully vaccinated returning residents.

Education Bureau statistics show that some 19,300 students withdrew from Hong Kong schools in the 2020-21 school year, the South China Morning Post reported in May. That included about 5,280 from private and international schools.

Beijing has blamed the city’s education system for fostering the dissent that caused 2019’s anti-government unrest. Authorities are now instilling a curriculum that teaches children to memorize offenses criminalized by the security law, and teachers have been advised to report on children who breach that legislation. 

The “government should formulate clear and effective policies to minimize the dropouts of both students and teachers, and also tackle the impact of the dropouts,” the association of school heads said.

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