Local authorities on Tuesday seized a rural activist who has been leading a high-profile legal campaign against the use of forced sterilization and abortion in China, in an apparent effort to block him from meeting with senior government officials who had expressed support for his cause.

The detention of Chen Guangcheng, 34, a blind peasant who has been preparing a class-action lawsuit to challenge population-control abuses in the eastern city of Linyi, occurred a few days after he arrived in Beijing for meetings with lawyers and journalists. He was seized just as the Chinese government opened an international legal conference here.

Several men in plain clothes grabbed Chen when he left an apartment building on Tuesday afternoon, witnesses said. The men did not identify themselves, and Chen resisted, shouting for help as they dragged him across a parking lot and pushed him headfirst into an unmarked car with tinted windows, the witnesses said.

A small group of people, upset by seeing the rough treatment, surrounded the vehicle and prevented it from driving away. As two men held Chen down in the back seat, he could be heard screaming and appeared to be in pain.

Residents called Beijing police. Two uniformed officers arrived, consulted with the men who had seized Chen, then cleared a way for the car to leave. The officers said the men who seized Chen were police from China's Shandong province, where Linyi is located. Tu Bisheng, a friend who was with Chen at the time, said local officials from Linyi were also present.

"We feel this is extremely inappropriate," said Li Heping, one of the lawyers working with Chen. He said the Linyi officials appeared to be "taking revenge on him for trying to protect the rights of local citizens and exercising his right to criticize the government."

A spokesman for the Shandong public security bureau said he knew nothing about Chen's detention and declined to accept questions about the case.

Chen was seized just hours after meeting with a reporter who works for Time magazine, Tu said. Over the past few days, Chen also met with a Washington Post correspondent, diplomats from the U.S. Embassy and several lawyers in Beijing who have volunteered to help him sue officials in Linyi, a city of 10 million located about 400 miles southeast of Beijing.

In March, residents said, the Linyi government began requiring parents with two children to be sterilized and forcing women pregnant with a third child to have abortions. Officials also have been detaining family members of such people who fled, beating them and holding them hostage until their relatives return and submit to the operations, according to residents interviewed in Linyi.

Chen's attempt to organize a class-action lawsuit against Linyi was the subject of a report in The Washington Post on Aug. 27. At the time, officials in Beijing said the practices described by Linyi residents were illegal and expressed support for the lawsuit.

After publication of the article, the National Population and Family Planning Commission, the cabinet-level ministry that manages population growth in China, sent a team of officials to investigate the allegations in Linyi. The investigators tried to meet with Chen, but he had already traveled to Beijing.

In an interview before his arrest, Chen said he was thinking about meeting with commission officials, but was worried about being arrested.

A commission official, contacted by telephone, said the ministry was unaware of Chen's detention and could not immediately comment on it. The official said the ministry would try to contact Shandong authorities to determine what happened to Chen. The ministry considers the Linyi case a priority and will severely punish family planning officials who violate the law, the official said.

Provincial authorities wield tremendous power in China's one-party political system and often disobey ministries in the central government. But the seizure of Chen represents an unusually public act of defiance, which could embarrass the governing Communist Party as it seeks to project an image that it has abandoned coercive methods to limit population growth.

Local officials throughout China began using forced abortions and compulsory sterilization to enforce the one-child policy in the early 1980s, but the central government since the mid-1990s has tried to eliminate such practices and move toward a more flexible system of economic rewards and fines to slow population growth.

Jerome Cohen, a specialist on Chinese law at New York University who is teaching in Beijing this fall, said he met with Chen on Monday night and discussed the risks of the lawsuit with him. Chen was determined to press ahead, Cohen said.

"This seems to be a case of local officials who have blatantly abused their legal powers, and have no legitimate defense against the case he brought against them, resorting to extralegal methods to cut off his ability to pursue justice," Cohen said. "It's very, very sad, and another example of how rough the legal situation is in rural areas."

Chen Guangcheng, a blind farmer shown last month speaking with women in Linyi, China, was seized in Beijing in an apparent effort to block him from meeting with senior government officials who had expressed support for his cause.