VATICAN CITY (CNS) — In a letter to the world’s bishops, Pope Benedict XVI expressed regret that his lifting of the excommunications of four traditionalist bishops gave rise to a storm of protests and bitterness.

The pope said the controversy over Bishop Richard Williamson’s statements denying the extent of the Holocaust was “an unforeseen mishap” — one that could have been anticipated, however, by paying more attention to information easily available on the Internet.

The pope said he was particularly saddened at the reaction of some Catholics who seemed willing to believe he was changing direction on Catholic-Jewish relations and were ready to “attack me with open hostility.” He thanked “our Jewish friends” who helped clarify the matter and restore a sense of trust.

Excerpts from the letter were published by Italian media March 11, the day before the Vatican was planning to release the text. Catholic News Service obtained a copy of the letter in English. The pope said he was taking the unusual step of writing to the bishops because the episode had generated “a discussion more heated than any we have seen for a long time,” both inside and outside the church.