HONG KONG >> Hong Kong police fired volleys of tear gas in a popular shopping district as thousands took to the streets Sunday to march against China’s proposed tough national security legislation for the city.

Pro-democracy supporters in Hong Kong have sharply criticized China’s proposal to enact a national security law that would ban secessionist and subversive activity, as well as foreign interference and terrorism in the semi-autonomous territory. Critics say it goes against the “one country, two systems” framework that promises the city freedoms not found on the mainland.

On Sunday afternoon, crowds of protesters dressed in black gathered in Causeway Bay, a popular shopping district, to protest the proposed legislation. Protesters chanted slogans “Stand with Hong Kong,” “Liberate Hong Kong” and “Revolution of our times.”

Prominent activist Tam Tak-chi was arrested during the protests for what police said was an unauthorized assembly. Tam said he was giving a “health talk” and was exempt from social-distancing measures that prohibit gatherings of more than eight people.

The protests are a continuation of a monthslong pro-democracy movement that began last year and has at times descended into violence between police and protesters.

The bill that triggered Sunday’s rally was submitted at China’s national legislative session on Friday. It is expected to be passed on May 28. It would bypass the city’s legislature and allow the Hong Kong government to set up mainland agencies in the city that would make it possible for Chinese agents to arbitrarily arrest people for activities deemed to be pro-democracy.

U.S. Secretary of State Mike Pompeo has called the move “a death knell for the high degree of autonomy” that Beijing had promised Hong Kong.

The erosion of Hong Kong’s freedoms prompted Chris Patten, the last British governor of Hong Kong prior to its handover to China in 1997, to condemn what he called “a new Chinese dictatorship.”

“I think the Hong Kong people have been betrayed by China, which has proved once again that you can’t trust it further than you can throw it,” Patten said in an interview with The Times of London.

Bernard Chan, a top-level Hong Kong politician and delegate to the National People’s Congress in Beijing, defended national security legislation pushed by China, saying it was written into Hong Kong’s Basic Law — the city’s mini-constitution — but never enacted.

Chan, a pro-Beijing lawmaker, expressed concern that Hong Kong will inevitably face economic hardship given trade frictions between the U.S. and China.

“I think we are definitely the collateral damage being dragged into this thing. But then, I don’t think there’s any alternatives,” Chan said.

“But with or without this law, honestly, the U.S. and China will always going to be continuing this loggerhead for quite some time to come,” he said. “China will remain as a threat to the U.S. in terms of the … world economic dominance.”