Hong Kong police used water cannon to break up the first protest since China introduced sweeping security legislation and police made first arrests under it, warning of punishment for advocating “secession or subversion”.
Thousands of protesters gathered downtown on Wednesday for an annual rally marking the anniversary of the former British colony’s handover to China in 1997.
Beijing unveiled on Tuesday the details of the national security law after weeks of uncertainty.
“I am scared of going to jail but for justice I have to come out today, I have to stand up,” said one 35-year-old man who gave his name as Seth.
Crowds spilling out into the streets chanted “Resist till the end” and “Hong Kong independence”.
Police fired water cannon to chase them away and later said they made 30 arrests for illegal assembly, obstruction, possession of weapons and violating the new law.
“You are displaying flags or banners/chanting slogans/or conducting yourselves with an intent such as secession or subversion, which may constitute offences under the … national security law,” police said in a message displayed on a purple banner.
The law will punish crimes of “secession”, “subversion”, “terrorism” and “collusion with foreign forces” with up to life in prison and officially set up mainland security agencies in Hong Kong for the first time, with powers beyond city laws.
China’s parliament adopted it in response to months of pro-democracy protests last year triggered by fears that Beijing was stifling the city’s freedoms, guaranteed by a “one country, two systems” formula agreed when it returned to Chinese rule.
Authorities in Beijing and Hong Kong have repeatedly said the legislation is aimed at a few “troublemakers” and will not affect rights and freedoms, nor investor interests.
But critics fear it will crush the freedoms that are seen as key to Hong Kong’s success as a financial centre.