VATICAN CITY — The Vatican on Thursday excommunicated two bishops ordained by China's state-controlled church without the pope's consent, escalating tensions as the two sides explore preliminary moves toward improving ties.

The Vatican also excommunicated the two bishops who ordained them, saying church law mandates excommunication for bishops involved in ordinations without Vatican approval.

Vatican spokesman Joaquin Navarro-Valls cited Article 1382 of the Roman Catholic Church's canon law.

That article states that "both the bishop who, without a pontifical mandate, consecrates a person a bishop, and the one who receives the consecration from him, incur a 'latae sententiae excommunication,'" which means they are automatically excommunicated.

Earlier, Navarro-Valls said Pope Benedict XVI was deeply saddened by news of the ordinations, which have occurred in recent weeks.

"It is a great wound to the unity of the church," Navarro-Valls said in a statement.

Chinese Foreign Ministry officials were not available to comment on the excommunications.

But earlier, a duty officer referred to an April 30 statement issued after the Vatican criticized the first ordination.

"The criticism toward the Chinese side by the Vatican is groundless," that statement said.

"We hope the Vatican can respect the will of Chinese church and the vast numbers of priests as well as its church members so as to create good atmosphere for the improvement of Sino-Vatican ties."