HONG KONG • Chinese police have said for the first time that they are holding three Hong Kong booksellers who went missing on the mainland last year.
The admission confirms what many in the semi-autonomous city have suspected, and will reinforce fears that rights guaranteed under the principle of "One Country, Two Systems" are being eroded.
The three men all work for the Mighty Current publishing house, based in Hong Kong and known for provocative titles critical of the Chinese government.
Five booksellers from the firm have disappeared since last October. All have now turned up in China, drawing international criticism.
The European Parliament has called for the immediate release of the five men. It said in a statement: "The resolution calls for their immediate safe release. It also calls for the immediate release of all other persons arbitrarily arrested for exercising their rights to freedom of expression and publication in Hong Kong."
Asked about the statement, Chinese Foreign Ministry spokesman Lu Kang told a regular news briefing: "Hong Kong affairs are China's domestic matter. We firmly oppose any country interfering in China's domestic affairs."
Washington had also called on Beijing on Monday to explain the disappearances, with a State Department spokesman saying the incidents "raise serious questions about China's commitment to Hong Kong's autonomy".
Booksellers Lui Por, Cheung Chi Ping and Lam Wing Kee disappeared in southern China in October last year.
A fourth missing member of the company, Mr Gui Minhai, a Swedish national, was paraded weeping on Chinese state television last month, when he said he had turned himself in for a fatal driving accident 11 years ago.
Mr Gui had failed to return to Hong Kong from a holiday in Thailand in October.
In a letter to Hong Kong police, the Guangdong Provincial Public Security Department said the three men being held "were suspected to be involved in a case relating to a person named Gui, and were involved in illegal activities on the mainland".
"Criminal compulsory measures were imposed on them and they were under investigation," said the letter, released by Hong Kong police late on Thursday.
Enclosed was also a letter from the fifth missing bookseller, Mr Lee Bo, Hong Kong police said.
Mr Lee's case has sparked the strongest backlash as he was the only one of the men to have disappeared while in Hong Kong.
Lawmakers and activists have accused the mainland authorities of snatching Mr Lee from the city, contravening Hong Kong's laws that do not allow Chinese police to operate within the territory.
The new letter from Mr Lee said the Chinese authorities had told him Hong Kong police wanted to meet him on the mainland, according to the Hong Kong police statement. "He stated that he did not need to meet with police at the moment. He would contact police should he need to meet with police," the statement said.
Some supporters of the booksellers believe they were targeted over a new book they were about to publish titled Xi Jinping And His Lovers.
One of the authors of the book, Chinese writer Xi Nuo, based in the United States, urged China to release the men.
"They are not responsible for this. I'm responsible for this. I want to... tell the Chinese government: Let the five guys go home," he told the BBC.
Hong Kong Chief Executive Leung Chun Ying, speaking to reporters yesterday, urged the public not to speculate on the investigations.
He said the Hong Kong government will continue to pursue the case - despite Mr Lee asking the city's police not to do so, the South China Morning Post reported.
AGENCE FRANCE-PRESSE, REUTERS