TAIPEI, Taiwan (AP) — Hundreds of people marched in Taiwan's capital on Sunday to demand the release of 12 Hong Kong anti-government protesters who were arrested by mainland Chinese authorities in August.

The 12 were allegedly traveling illegally by boat to Taiwan when Chinese authorities detained them. They are now facing formal charges for illegal border crossings in Shenzhen, a southern Chinese city that borders Hong Kong, a semi-autonomous Chinese territory.

On Friday, Saturday and Sunday, people demonstrated in at least a dozen cities across the world — from New York to Vancouver to Adelaide in Australia — in support of those who were arrested, in a campaign called #save12hkyouths. Prominent Hong Kong activists Joshua Wong and Nathan Law helped launch the campaign on social media.

In the crowd in Taipei on Sunday were activists from several Taiwanese organizations, as well as other residents of the self-ruled democratic island and many Hong Kongers. With many dressed in black and wearing face masks, they marched through the city, shouting “Glory to Hong Kong.”

Taiwan and China split amid civil war in 1949, and Beijing has cut off ties with Taiwanese President Tsai Ing-wen's government over her refusal to accept its demand that she recognize the island as a part of China to be unified with the mainland eventually under the same “one country, two systems” policy enacted in Hong Kong.

Tsai's election last January to a second, four-year term came after the repression of last year's pro-democracy protests in Hong Kong solidified public opinion in Taiwan against moves toward accepting rule by Beijing.

Tsang Cheung-kui, who moved from Hong Kong to Taiwan in February, said it was important to him as a Hong Konger to demonstrate. “Those of us Hong Kongers in Taiwan want to come support them," he said. “It's very obvious, Hong Kong is no longer Hong Kong. But we haven't given up on Hong Kong.”

Unlike in 2019, when Tsang took part in Hong Kong's anti-government protests to demand protections for the city's democratic freedoms, the message this time was different.

“A lot of us protesters, we have this mindset that we want the world to know Hong Kong is no longer the same,” Tsang said. "Don't think that Hong Kong is like before where there was democracy, freedom and rule of law. Now this is completely nonexistent.”

Jeff Hou, a Taiwanese resident who brought his 13-year-old son to the rally, said it was important to march for democratic freedoms. “As long as it has to do with democracy, we should come stand out here," he said. "Democratic freedoms are very important to us Taiwanese.”

Emma, a 27-year-old protester who declined to give her full name for reasons of safety, said she was concerned about the fate of the 12 who were arrested. “I’m doubtful of whether they were arrested legally, and whether rights are being upheld after being arrested," she said. "I wanted to come to this march in support of them.”

Many Hong Kong residents have been looking into moving to Taiwan since China pushed through a wide-ranging national security law for the city in June.

Those arrested in August range in age from 16 to 33. Their families are now campaigning to use their own lawyers instead of the court-appointed ones from the Chinese side.