Jiang Tianyong, an activist lawyer in Beijing, vanished Feb. 19, a day before the first protest planned in the Chinese capital and other cities. Jiang has not been heard from since. The anonymous group posting to the website Boxun.com called this week for fresh protests Sunday.

Jiang and two other human rights lawyers, Tang Jitian and Teng Biao, have disappeared into China's labyrinthine security system in the past two weeks, says China Human Rights Defenders, a Hong Kong-based group. More than 100 other people have had their movements restricted, and six activists face subversion charges, possibly for posting information online about the "Jasmine Rallies," according to the group.

Jiang's wife, Jin Bianling, says she has tried to persuade her husband to switch to a safer profession. She fears the worst.

"He might be sentenced on some charge," says Jin of her 39-year-old husband. "But I am most worried they will torture him. He has high blood pressure, but the police refuse to deliver his medicine. I worry about his personal safety."

Several foreign journalists were warned by Chinese police this week that they risk having their visas revoked if they continue to report on the Jasmine Rallies.

The disappearances began shortly after website postings last month called on Chinese to "take a stroll" in specific spots in dozens of cities in China on Sunday afternoons. Organizers ridicule the Communist leadership and its slogans and accuse the government of corruption, asking Chinese where the money is going from the sale and leasing of properties to foreign companies.

"We only need one slogan for our Jasmine Revolution, and that is ... terminate one-party rule," one posting said, according to the South China Morning Post, a Hong Kong-based newspaper.

The post was carried on Twitter and other social networking sites, but the website is blocked inside China, so it is not known how many people are aware of the calls. The word "jasmine" has been censored from many websites, the newspaper reports.

On Feb. 27, hundreds of uniformed and plainclothes police broke up crowds in Beijing and Shanghai and detained more than a dozen people, mostly journalists who had arrived to see what would happen. Shanghai police used whistles to disperse a crowd of about 200, the Associated Press reported.

Though the calls have not led to any observable protests, they have provoked the government into unusually harsh police actions, experts say.

The three lawyers' detention appears to be the start of a criminal process, says Jerome Cohen, a U.S. expert on Chinese law and senior fellow at the Council on Foreign Relations. "The oppression is getting worse than it has been in some years."

The Chinese government threatened to revoke the visas of foreign correspondents if they continue to try to report on demonstrations. Dozens of foreign journalists who tried to cover gatherings Sunday were summoned to police stations for interviews, the Foreign Correspondents Club of China said Thursday in a warning to members.

In a statement Tuesday, the Jasmine organizers said, "China's government clearly shows its horror and fear of the people, as if facing a deadly enemy. A modest amount of people, just by walking, has demonstrated people's power, and the government's response has revealed its weakness to the world," the Post said.

The Chinese government has banned reporting in areas of Shanghai and Beijing where the organizers have scheduled the silent protests.

The U.S. Embassy in Beijing says it has repeatedly raised with authorities the disappearance of Gao Zhisheng, a self-taught lawyer who has represented members of the banned Falun Gong spiritual movement and Chinese Christians. Gao was imprisoned for 14 months and upon his release in March last year described to the Associated Press how he was tortured by his jailers. He asked that his interview not be published until he was safe. Two weeks later, Gao vanished. China has refused to discuss his case with the United States or his relatives. The AP subsequently published a story about his interview.

Three police officers at separate stations believed to be involved in Jiang Tianyong's detention refused to answer questions when contacted by USA TODAY. His wife's concerns, and lack of information, are commonplace among the relatives and friends of people targeted by Chinese security forces.

"I can't sleep at night," says Pang Jinhua, mother-in-law of lawyer Teng Biao, missing since Feb. 19. "I don't understand why he has been taken. He takes on cases to help ordinary people. He doesn't break rules or do anything bad," she says.

Cohen says lawyers such as Teng draw attention by defending "sensitive" clients such as dissidents or members of Falun Gong, whose members have been severely repressed.

"These are three terrific people, and China's future will be better if they are participating," Cohen says. "Jiang Tianyong was a schoolteacher but so interested in human rights he felt he better become a lawyer. He's a totally admirable person."

Cohen says President Obama and Secretary of State Hillary Rodham Clinton need to continue to speak publicly about such cases.

"It may not get them out but it increases the pressure," he said.

Other rights lawyers say they are receiving increased police surveillance.

Lawyer Li Heping says his home is under constant watch and up to four plainclothes policemen tail him when he leaves.

"I told the police I have nothing to do with the Jasmine Rallies and I'm not participating, but still they want to control me. To the authorities, " 'every bush and tree seems an enemy,' " Li says, using a Chinese phrase.

In Chengdu, a major city in southwestern China, friends of writer and blogger Ran Yunfei are shocked over his detention Feb. 20 and the subsequent charge of "subversion of state power," says Wang Yi, a local church leader.

The clampdown shows "the government is very nervous, and their reaction is to pre-empt social discontent merging with the mobility of activists and the power of the Internet, as happened in the Middle East," says Wang Songlian, a researcher for China Human Rights Defenders.

As world attention is focused elsewhere, China's security forces are seizing the opportunity to crack down on perceived opponents, she says.

Jin Bianling hopes her husband, Jiang, will be released. Even if he is set free, she doubts Jiang will curb his efforts on behalf of people targeted as enemies of the authoritarian state.

"He says that helping disadvantaged people is the most meaningful thing he can do," she says.

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