Pope Benedict said today he was "deeply sorry" at the anger caused by his remarks on Islam and said a quote he used from a medieval text about holy wars did not reflect his personal thoughts.
"I am deeply sorry for the reactions in some countries to a few passages of my address at the University of Regensburg, which were considered offensive to the sensibility of Muslims," he told pilgrims at his Castelgandolfo summer residence, where security has been tightened over fears of reprisal attacks.
"These in fact were a quotation from a medieval text, which do not in any way express my personal thought. I hope this serves to appease hearts and to clarify the true meaning of my address, which in its totality was and is an invitation to frank and sincere dialogue, with mutual respect," he said.
Pressure had been mounting on Benedict to issue a personal apology after his comments about Islam sparked Muslim fury across the world.
The Vatican said yesterday the Pope was sorry Muslims had been offended and that his comments had been misconstrued, but Muslim countries and religious groups remained angry at what they said portrayed Islam as a religion tainted with violence.
I hope this serves to appease hearts and to clarify the true meaning of my address, which in its totality was and is an invitation to frank and sincere dialogue, with mutual respectPope Benedict
In a statement posted on the internet, an Iraqi insurgent group today threatened the Vatican with a suicide attack over the Pope's remarks.
In Iran, theological schools closed today in protest and Etemad-e Mellinewspaper said senior clerics demanded an immediate apology. The English-language Tehran Timescalled his remarks "code words for the start of a new crusade".
Morocco withdrew its ambassador to the Vatican yesterday, calling the Pope's remarks "offensive".
Egypt's Muslim Brotherhood said Pope Benedict had not made a "clear apology" for his remarks.
"It does not rise to the level of a clear apology and, based on this, we're calling on the Pope of the Vatican to issue a clear apology that will decisively end any confusion," Brotherhood deputy leader Mohammed Habib told Reuters. Mr Habib had earlier described the Pope's remarks on Sunday as a "sufficient apology".
The Muslim Brotherhood in Egypt is a political Islamist opposition group which has inspired similar movements across the Arab world.
Mehmet Aydin, a minister overseeing religious affairs in Turkey, which Benedict is due to visit in November, also said it was inadequate. "You either have to say this 'I'm sorry' in a proper way or not say it at all," he said. "Are you sorry for saying such a thing or because of its consequences?"
In the speech in Germany on Tuesday, the Pope referred to criticism of the Prophet Mohammad by 14th century Byzantine Emperor Manuel II Palaeologus. The emperor said everything Mohammad brought was evil "such as his command to spread by the sword the faith he preached
Using the terms "jihad" and "holy war", the 79-year-old Pope said violence was "incompatible with the nature of God".
But the Vatican's secretary of state, Cardinal Tarcisio Bertone, said in a statement the Pope "had absolutely no intention" of presenting Emperor Manuel's opinions on Islam as his own.
"The Holy Father thus sincerely regrets that certain passages of his address could have sounded offensive to the sensitivities of the Muslim faithful," Cardinal Bertone said in a statement. He said the Pope, elected 17 months ago, confirmed "his respect and esteem for those who profess Islam" and hoped his words would be understood in their "correct meaning".
The academic speech was meant as a "a clear and radical rejection of the religious motivation for violence, from whatever side it may come," the Cardinal added.
Iraqi Shia leaders called earlier for Pope Benedict to apologise for the comments.
"We strongly condemn these remarks and we demand that the Vatican Pope apologises clearly and honestly for what he has said against Islam," the Supreme Council for the Islamic Revolution in Iraq (SCIRI) said in a statement.
"We call on this occasion for all the religious leadership of the world ... to follow the example of Islam and teach compassion and mercy, and oppose (extremist) ideology that teaches killing and destruction."
SCIRI is one of the two main Shia groups in the ruling coalition. The other, followers of cleric Moqtada al-Sadr, criticised the Pope during prayer sermons on Friday, while the leader of the main Sunni faction denounced the Pope yesterday.
The backlash over the Pope's comments has cast doubt on his planned visit to Turkey in November. Prime Minister Tayyip Erdogan said before the Vatican statement the Pope's comments were "ugly and unfortunate" and should be withdrawn.
However, Foreign Minister Abdullah Gul said today he expected the visit to go ahead. Aksamnewspaper said Mr Gul had also written a letter to Benedict urging him not to cancel the trip, saying it was an important opportunity to foster dialogue between different cultures.