Beijing - China has arrested a 73-year-old underground bishop, a US-based Catholic group said in a statement.

Julius Jia Zhiguo, bishop of the unregistered or "underground" Roman Catholic congregation of Zhengding village in northeast China's Heibei province, was arrested by Chinese officials Sunday morning, the Cardinal Kung Foundation said.

It was the 12th time Jia has been arrested since 2004, the foundation said in a statement issued late Sunday. He has spent
18 years in prison.

He was last arrested in August last year, and released again in December.

"We do not know where Bishop Jia is detained at this time. We also do not know why he was arrested again this time," said Joseph Kung, head of the foundation.

After his release in December, Jia was placed under house arrest, confined to the living quarters of his cathedral in Heibei and not allowed to receive any visitors except for a few rare occasions when the visits were supervised and accompanied by government officials, Kung said.

Jia was consecrated bishop of Zhengding in 1980, mandated by Pope John Paul II, and leads a Roman Catholic community with approximately 110,000 members.

Two Catholic churches exist in China. The official state-run church does not recognize the authority of the Pope.

Jia is one of approximately 40 underground bishops in China, every one of whom is either in prison, missing, under house arrests, or under surveillance, Kung said.

"The persecution of religious believers is very much alive in China and ongoing regardless of the fact that the Olympics games has just been held in China and closed (Sunday)," Kung said. (dpa)