Sweden's Foreign Minister Margot Wallstrom on Friday condemned China's detention of two Swedish nationals as "unacceptable", as the European Union called in a statement for a "swift resolution" of the case.

"We have said, through diplomatic channels, that it is unacceptable, that we want information and we want to see them," Wallstrom told the Swedish TT press agency.

One of those detained was activist, Peter Dahlin, who worked for the Chinese Urgent Action Working Group.

He was detained two week ago at Beijing airport while attempting to board a plane bound for Thailand.

State broadcaster China Central Television (CCTV) on Tuesday aired footage of a dazed and harried looking Dahlin apologising to China for his alleged actions. The official news agency Xinhua also published quotes from the video.

The previous day CCTV had broadcast a video of Hong Kong bookseller Gui Minhai, a naturalised Swedish citizen, confessing to a years-old mainland drink-driving offence and saying he did not want Stockholm to interfere with his case.

China-born Gui was rumoured to be preparing a tell-all book about the love life of President Xi Jinping. He disappeared from Thailand late last year before reappearing on Chinese national television in police custody.

While forced public confessions are an old practice in Communist China, they have experienced a resurgence since President Xi took power in 2012.

"It is completely unacceptable that they were made to parade themselves in this manner," on public television, said Wallstrom. "This kind of behaviour is not acceptable."

Beijing only rarely accuses foreigners of endangering state security, a crime which can receive a heavy sentence.

"The EU expects a swift resolution of this case in accordance with international human rights standards," a spokesman for the bloc said in a statement on Dahlin's detention.

"Mr Dahlin's arrest and detention are part of a worrying trend and call into question China's respect for the rule of law and for its international human rights obligations," the statement said.

Meanwhile a lawyer for Chinese activist Zhang Haitao said Friday that his client has been jailed for 19 years in the volatile northwestern Xinjiang region over online posts criticising the ruling Communist Party and for giving interviews to foreign media.

Journalism advocacy group Reporters Without Borders on Thursday urged the European Union to impose sanctions on Chinese state media over the "forced confessions".

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