BEIJING — Chen Guangcheng, the blind rights lawyer who has been under extralegal house arrest in his rural village for the past 19 months, has escaped from his heavily guarded home and is in hiding in the capital, rights advocates and Chinese officials said on Friday.


The activist Hu Jia told the BBC that Mr. Chen had scaled a wall, was driven to Beijing, and was in the American embassy. An official in the Chinese Ministry of State Security confirmed that Mr. Chen had managed to reach the embassy, though American officials would not confirm that report.


Those who have spoken to Mr. Chen say he slipped away from his captors on Sunday evening in Shandong Province, where he has been held incommunicado since his release from prison in September 2010. They said Mr. Chen was not seeking to leave China, but would try to negotiate his freedom with Chinese authorities.


“He is reluctant to go overseas and wants only to live like a normal Chinese citizen,” said Bob Fu, president of China Aid, a Christian rights organization based in Texas that had been in touch with him as recently as Friday morning.


The escape would represent a significant public relations challenge to the Chinese government, which has long sought to deny reports that local officials in Dongshigu village were keeping Mr. Chen and his wife locked in their home even though there are no legal charges against him.


The case could also present a major new challenge to the United States, which was thrust into another delicate internal political dispute in China in February. At that time, Wang Lijun, a senior police official from the region of Chongqing, sought refuge in the American consulate in Chengdu, revealing details about the killing of a British businessman and setting off a cascade of events that led to the downfall of Bo Xilai, who was a member of China’s Politburo.


American diplomats said they determined Mr. Wang’s case did not involve national security, and they turned him over to Chinese security officials, prompting criticism in Washington about their handling of the case.


But if Mr. Chen is now on the grounds of the embassy in Beijing, Obama administration officials are likely to be far more cautious in handling his case, given that he is one of China’s most internationally recognized dissidents and has been the subject of extralegal abuses in China for many years.


Secretary of State Hillary Clinton has addressed Mr. Chen’s case on several occasions, most recently in a speech on Asian policy last November that prompted a sharp rebuke from the Chinese government. “When we see reports of lawyers, artists, and others who are detained or disappeared, the United States speaks up both publicly and privately,” she said then. “We are alarmed by recent incidents in Tibet of young people lighting themselves on fire in desperate acts of protest, as well as the continued house arrest of the Chinese lawyer Chen Guangcheng. We continue to call on China to embrace a different path.”


On Friday, however, the State Department’s spokeswoman, Victoria Nuland, said she would make no comment about Mr. Chen’s escape or his whereabouts. The White House also declined to comment, and a scheduled briefing on Mrs. Clinton’s visit to China next week — which Mr. Chen’s escape will almost certainly overshadow — was postponed.


“Chen Guangcheng is a very strong candidate for asylum,” said Susan L. Shirk, a former State Department who is now a professor with the University of California, San Diego. “A blind lawyer who is being persecuted for exposing forced abortions? I don’t think there’s any question about it.”


An asylum bid, however, would roil the Obama administration’s careful cultivation of the Chinese in an effort to improve cooperation, especially on international issues like Iran’s nuclear activity and North Korea’s recent belligerence. As in the exploding scandal surrounding Bo Xilai, the administration has sought to keep itself out of China’s internal politics.


“It’s very challenging for the United States,” Ms. Shirk said, “because the United States has tried very hard not to get itself in the middle of the domestic political process in China right now.”


A spokesman for China’s Foreign Minister on Friday said he had no information about the episode, but one Chinese intelligence officer expressed frustration and bewilderment that Mr. Chen had evaded his captors and that he might have entered the embassy.