The Vatican firmly condemned the recent attack against a U.S. consulate in Libya, which led to the death of a U.S. ambassador, three U.S. personnel and at least 10 Libyans.

“The very serious attack organized against the United States’ diplomatic mission in Libya,” it said, “calls for the firmest possible condemnation on the part of the Holy See.

Nothing, in fact, can justify the activity of terrorist organizations and homicidal violence,” said Jesuit Father Federico Lombardi, the Vatican spokesman, in a written statement released Sept. 13.

The U.S. ambassador to Libya, Christopher Stevens, and three staff members were killed during what appeared to be a pre-planned, sophisticated armed attack against the U.S. consulate in Benghazi Sept. 11.