Islamic extremists attacked the US consulate in Benghazi on 11 September in retaliation for a film produced in America that ridiculed the prophet Muhammad.
In a declaration on 12 September the Vatican said the violence was "unacceptable", but emphasised that the angry reaction was "the serious consequences of unjustified offence and provocations against the sensibilities of Muslim believers".
However, in a tougher statement just 24 hours later, it expressed the "firmest possible condemnation" of the American deaths and said that "nothing, in fact, can justify the activity of terrorist organisations and homicidal violence".
The first Vatican statement was issued with a translation in Arabic, but the second one was not.