https://www.bbc.com/news/world-asia-china-53336191
Now Education Minister Kevin Yeung says schools must stamp out such demonstrations.
Mr Yeung said the song Glory to Hong Kong was "closely related to the social and political incidents, violence and illegal incidents that have lasted for months," according to Reuters news agency.
"Schools must not allow students to play, sing or broadcast it in schools," he said.
Additionally authorities said students must not form human chains, chant slogans or express other political messages.
Now Education Minister Kevin Yeung says schools must stamp out such demonstrations.
Mr Yeung said the song Glory to Hong Kong was "closely related to the social and political incidents, violence and illegal incidents that have lasted for months," according to Reuters news agency.
"Schools must not allow students to play, sing or broadcast it in schools," he said.
Additionally authorities said students must not form human chains, chant slogans or express other political messages.