A Hong Kong teacher’s licence has been removed after being accused of promoting the territory’s independence in the classroom.
Hong Kong’s leader Carrie Lam said it was important to weed out “bad apples” from the education system.
Officials in Beijing believe schools have been helping to foment opposition to China’s communist party.
Hong Kong’s largest teachers’ union has accused Hong Kong authorities of conducting an unfair investigation.
Rights group Amnesty International said the sacking sent an ominous message to teachers in Hong Kong about the discussion of politics in schools.
But Ms Lam insisted that the teacher’s removal was the result of a “thorough” probe.