Twelve Hongkongers who fled the city amid an ongoing crackdown on participants in last year's protest movement weren't "democracy activists being oppressed," the city's leader Carrie Lam told journalists on Tuesday.While Lam said her government would provide the detainees and their families with the "needed and feasible" assistance, she said their treatment by the mainland authorities was entirely appropriate."Twelve Hong Kong residents were suspected of illegally entering mainland China ... and so they were detained by mainland Chinese law enforcement," Lam told a regular news briefing. "It is obvious that this case falls within mainland China's jurisdiction."She added, in comments reported by Reuters: "The reason for them leaving Hong Kong seems to be that they were running away from legal responsibility.""I want to set the record straight, because certain local and overseas individuals tried to shift the attention, describing them as democracy activists being oppressed," she said.While the Hong Kong authorities have called on other jurisdictions not to "harbor" people wanted on criminal charges in Hong Kong, they have repeatedly said they won't "interfere" in the cases of the 12 Shenzhen detainees."All 12 are suspected of committing crimes in Hong Kong, according to the city's security bureau, with 10 of them wanted for manufacturing or possessing explosives, arson, rioting, assaulting police officers, or possession of offensive weapons.Hong Kong arrests, prosecutionsAuthorities in the city are bringing hundreds of protest-related prosecutions dating from the anti-extradition and pro-democracy protests that began in June 2019 on a range of charges including unlawful assembly, assault, arson, and rioting.Thousands of people have been arrested since the movement began. A U.S. State Department report warned in March that the prosecutions of activists had infringed on the rights of Hongkongers to peaceful assembly and protest.The 12 Hongkongers are aged 16 to 33, and are being held on suspicion of "illegal immigration" at the Yantian Detention Center in the southern Chinese city of Shenzhen, which borders Hong Kong.They were intercepted by the China Coast Guard after they tried to escape by speedboat to the democratic island of Taiwan last month.Chinese foreign ministry spokeswoman Hua Chunying, who referred to the 12 on Twitter as "elements attempting to separate Hong Kong from China," said on Tuesday that only one is suspected of "colluding with foreign powers" under a draconian national security law imposed by the ruling Chinese Communist Party on Hong Kong from July 1.The family members of six of the detainees held a press conference on Saturday, calling on the Hong Kong authorities to bring them back to the city as soon as possible.Growing concernsConcerns are growing over the lack of access to lawyers hired by their families and to adequate medical care.Pro-democracy lawmaker James To accused Lam's administration of operating a "double standard" when it came to Hong Kong detainees overseas."If the Hong Kong government believes that these 12 people have broken Hong Kong laws, shouldn't they be requesting that mainland China return them?" To said."[They] have already said that the five Hongkongers held in Taiwan [for illegal immigration] should be returned."He called on the Hong Kong authorities to do more to support the 12 detainees."The family members would like the Hong Kong government to show more concern, and to protect their rights and interests," To said.Reported by Gigi Lee for RFA's Cantonese Service. Translated and edited by Luisetta Mudie.