BEIJING (AP) - An elderly bishop in China's underground Catholic church has been detained again by police, nine months after his release from their custody, a U.S.-based monitoring group said Thursday.

Bishop Jia Zhiguo, 73, was taken away Tuesday by security agents in the northern city of Zhengding, the Cardinal Kung Foundation said in a statement. It was not immediately clear why Jia was detained or where he was being held, the group said.

A man who answered the telephone at the Zhengding Religious Affairs Bureau referred questions to the local government. Officials at the Zhengding government office and public security bureau said they had never heard of Jia and hung up without giving their names or any other details.

Jia was last released in September 2006 after being held for 10 months by local authorities. The reason was never made public but religious groups say Jia has been repeatedly detained over his refusal to affiliate himself with the Communist Party-controlled Catholic Patriotic Association.

"He was not even allowed to step out of the courtyard of his residence, was not allowed to administer the 'Last Rites' for his dying parishioners, and was not allowed any visitors," the foundation said.

China, which broke ties with the Vatican in 1951, demands that Catholics worship only in churches approved by the state-controlled group, which does not recognize the pope's authority.

Worship is allowed only in government-controlled churches, which recognize the pope as a spiritual leader but appoint their own priests and bishops.

Many Chinese Catholics, however, remain loyal to the Vatican and risk arrest by worshipping in unofficial churches and private homes. They are frequently harassed, fined and sometimes sent to labor camps.

The Cardinal Kung Foundation is named for the late Cardinal Ignatius Kung Pinmei of Shanghai, who spent 30 years in Chinese prisons and died in the United States in 2000 at age 98.

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