The head of Australia's Catholic Church has said the violent reaction to comments by Pope Benedict XVI on Islam justified the Pontiff's main fears.

Cardinal George Pell, the leader of over five million Catholics in Australia, said he was pleased there had been no violence in Australia in reaction to Pope Benedict's use of a medieval quotation on Islam and holy war.

But he criticised acts of violence elsewhere, observing that they showed the link for many Islamists between religion and violence and their refusal to respond to criticism with rational arguments.

Some Australian Muslim leaders said the comments by both Pope Benedict and Cardinal Pell should be condemned.