Hong Kong lawmakers and relatives of 12 Hong Kongers being held in Shenzhen revealed they have not heard from the detainees in nearly three weeks and have joined the U.S. Secretary of State in asking for legal assistance from Hong Kong Chief Executive Carrie Lam for their release.

The individuals – 11 men and one woman – were arrested last month en route to Taiwan by boat to avoid persecution in Hong Kong under the newly enacted National Security Law. They have been charged with unlawfully crossing the border.

Family representatives of the detained spoke publicly on the matter for the first time on Saturday after trying for the past three weeks to acquire legal assistance on the mainland.

"The fate of the 12 people is to become a diplomatic chip for the [Chinese Communist Party]" Legislative Council member Eddie Chu Hoi-dick noted in a Facebook post after a Saturday press conference, which he organized alongside fellow LegCo representative James To. The case "will be used as anti-Hong Kong independence political propaganda," Chu wrote.

The detainees, including two British National Overseas passport holders and a Portugese citizen, were en route to Taiwan from Hong Kong when their speedboat was apprehended by the Guangdong Coast Guard on August 23.

After taking them into custody, mainland authorities alerted Hong Kong police that the 12 Hong Kong residents were being held as part of "criminal compulsory measures" that can include arrest, detention, bail pending trial or residential surveillance.

"Police would notify their families as soon as possible of the criminal compulsory measures imposed on them," the bureau told the South China Morning Post, adding that assistance would be available should they request it.

However, family members of the detainees told the media on Saturday that they had not heard any news of their detained relatives.

"I'm very worried. I don't know if he's safe and sound, if he's still alive," said the mother of 29-year-old surveyor Li Tsz-yin, who was on bail in Hong Kong for rioting charges.

Pompeo Weighs in

The weekend press conference sparked a war of words between Chinese and American politicians, with the latter pushing for the individuals in question to receive legal representation.

U.S. Secretary of State Mike Pompeo said in a Twitter statement on Saturday that he was "deeply disturbed that Hong Kong democracy activists, arrested two weeks ago, have been denied access to lawyers of their choice."

He added: "We hope Chief Executive [Carrie] Lam's stated commitment to protecting the rights of Hong Kong residents is more than just words."

Among the detainees is Andy Li, the first person arrested under the new National Security Law for collusion with foreign forces and money laundering, along with 18-year-old University of Hong Kong student Kok Tsz-lun, who was charged with rioting by Hong Kong authorities and released on bail.

Secondary and university students make up nearly half of the arrested cohort; the youngest being a 16-year old high-schooler, a source told the South China Morning Post.

A Beijing spokeswoman fired back the same day, accusing the detainees of separatist activity. "The 12 people were arrested for illegally crossing the border. They are not democratic activists but elements attempting to separate Hong Kong from China," said Hua Chunying, the director of China's Foreign Ministry.

Since the security law came into effect in July, at least six people wanted by police for related offenses have fled the city, including prominent lawmaker Nathan Law and British consulate employee Simon Cheng.

After news of the arrests first broke in August, Hong Kong Police Chief Superintendent Chris Tang went on the record to stress it had not been a joint operation between mainland and Hong Kong authorities.

If they are charged as separatists under the new National Security Law, the 12 could face life in prison.

Five Others Trapped in Taiwan

While the 12 Hong Kongers languishing on the mainland were hoping to find safety in Taiwan, five more are trying to escape detention in the southern Taiwanese city of Kaohsiung, according to reports by Taiwan's Central News Agency (CNA) on Monday.

A boat holding five Hong Kong activists was boarded by the Taiwan Coast Guard sometime last month near the Dongsha Islands, CNA reported, citing unnamed security sources.

Taiwan President Tsai Ing-wen, who largely depended on the youth vote to retain power in the latest elections, previously pledged support for Hong Kong's pro-democracy activists.

But Taiwanese journalist Edd Jhong is now warning Hong Kong frontline protesters against fleeing to the island nation, according to an interview with RTHK on Sunday.

In response to inquiries by local media, Hong Kong's Security Bureau claimed it had not been alerted to the detentions. Taiwan authorities have not yet issued a statement.