A close observer of religious affairs in China, who asked not to be identified, described Vatican-Beijing tensions over the ordination of Chinese bishops as "very worrying."

"We don't know how these things will be played out, if this will be tit-for-tat. It's quite unsettling," he said."

China severed formal ties with the Vatican in 1951, with worship only permitted in government-controlled churches. However, many of China's estimated 10 million Catholics are believed to have remained loyal to Rome, preferring to gather in underground "home" churches.