The Rev. Liu Shaozhang, 20 nuns, two laymen and a seminarian in the underground church were arrested Wednesday in Luoyuan county, in southeastern Fujian province, the U.S.-based Cardinal Kung Foundation said.
Police beat Liu after taking him into custody, leaving the 38-year-old priest bleeding and spitting blood, the group said.
The report said a group of parishioners bought the release of two of the nuns, but the priest and 21 others were still in detention.
It provided no details on the circumstances of the group's arrest, but said the communist government was engaged in a campaign to force Catholics into the state-approved Chinese Catholic Patriotic Association.
"Because of the staunch resistance by the underground church to register with the government, the government intensified its persecution," foundation president Joseph Kung said in a statement.
Fujian province has an active and growing Catholic community and has come under renewed government pressure. Police in Jinfeng township detained another underground priest, the Rev. Gao Yihua, August 19 for celebrating Mass in a private home and held him for 11 days.
Mr. Lei, an official with the local government's religious affairs office, said the county had two Catholic churches, one official, one underground.
China's communist leaders set up the state church in 1951 and ordered Catholics to break with the Vatican to remove foreign influence. The government and church still refuse to allow the pope to appoint bishops, but worshippers and priests frequently move between the official and underground churches.