BEIJING — Authorities in the hometown of blind activist Chen Guangcheng have notched up restrictions on members of his extended family while he awaits permission in Beijing to travel abroad under an agreement between China and the U.S.

Chen Guangcheng's brother and sister-in-law have been placed under house arrest, his nephew is in police detention, and another half-dozen relatives face some form of restriction on their movements in their village in Shandong province, according to Chen, his lawyers and a rights group.

Chen's flight from abusive house arrest in Shandong and into the protection of U.S. diplomats — which led to an agreement with Beijing to let him study in the U.S. accompanied by his wife and children — has exposed the impunity of local officials and embarrassed the central government.

"I feel that Shandong's retribution against me has already started," Chen said in an interview Thursday from a hospital where he is being treated for injuries suffered during his dramatic escape from his guarded farm house.

His nephew, Chen Kegui, is believed to have been detained in relation to a clash he had with officials who reportedly broke into his home after discovering that the activist had escaped in late April.

Police in the activist's town are searching for the nephew's wife and have threatened to detain his mother, Chen Guangcheng said.

The Chinese Human Rights Defenders, a network of activists in China, said around a dozen of Chen's relatives in the village of Dongshigu are under some form of house arrest, including Chen's cousin and the cousin's son.

The group says its activists have direct contact with Chen Guangcheng's extended family members, and that they are vulnerable to retaliation by the local authorities.

"Even when the international spotlight is on Chen, his extended family has been cut off from communicating with the outside world, and his nephew is in police custody," said Wang Songlian, a researcher with the group. "What is going to happen once the spotlight shifts? It is extremely worrying."

A self-taught legal activist, Chen gained recognition among human rights campaigners at China and abroad for crusading for the disabled and fighting against forced abortions in his rural community. But he angered local officials in Shandong, where he was convicted in 2006 on what his supporters say were fabricated charges and served four years in prison. He then faced an abusive and illegal house arrest.

His dramatic flight to the U.S. Embassy in Beijing last month triggered a diplomatic standoff that was resolved with an agreement between the two government for Chen to travel to the U.S. to study.

But while he waits in a Beijing hospital for his family's travel documents, his extended family is increasingly coming under pressure over his escape, he said.

"I hope that this issue gets some attention and that lawyers are able to meet the family and sign to entrust the case to them," Chen said. "They won't let the lawyers enter the village and won't let them interact with the family. In turn, they are taking revenge on my family like this, it is simply too outrageous."