By David Willey
BBC News, Rome
The Vatican says it was surprised at Muslim reaction
The Vatican is seriously concerned at the possibility of acts of violence being staged against the tiny city state situated in the heart of Rome, after a barrage of criticism from Muslims in many countries against Pope Benedict XVI.
Pope Benedict's critical remarks earlier in the week about jihad, or Islamic holy war, have been the subject of hostile comment in many Islamic countries.
Security has been discreetly stepped up around and inside the walled Vatican City, although Pope Benedict himself is not in residence there at the moment.
He is resting after his recent trip to Germany at the Papal summer villa at Castelgandolfo, in the Alban Hills 30km (20 miles) from Rome.
The outrage expressed by Muslim clerics and commentators at the Pope's quotation from a 600-year-old book containing the sayings of a Christian emperor of ancient Byzantium appears to have taken Vatican officials by surprise.
The emperor spoke of "the Prophet Muhammad's command 'to spread by the sword the faith he preached'".
The context of the Pope's quotation about the unreasonableness of spreading faith by violent means was an academic lecture on the relationship of faith and reason for professors and graduate students of the University of Regensburg in southern Germany, where the Pope once taught.
"God is not pleased by blood and not acting reasonably is contrary to God's nature... Whoever would lead someone to faith needs the ability to speak well and to reason properly, without violence and threats.
Benedict said he was making a philosophical point
"To convince a reasonable soul, one does not need a strong arm or weapons of any kind or any other means of threatening a person with death," the Pope quoted the emperor as saying.
Within 24 hours, as news of the Pope's speech spread through the Islamic world, the protests started multiplying. An apology was demanded.
The Pope could also have mentioned the violence of Christian crusaders against Muslim believers, but chose not to do so.
The Pope had specifically stressed in his lecture that he was not giving a history lesson, but making a philosophical point.
At the end of November, Pope Benedict is due to visit Turkey, a secular, predominantly Muslim country. He has already come under fire from a leading Muslim cleric there who has accused him of prejudice and bias and called him "hostile and arrogant".
But on the day when there has been a changing of the guard in the upper echelons of the Vatican - with the arrival of an Italian cardinal, a former close aide of the Pope, to take up his new appointment of secretary of state - the number two position inside the Vatican, preparations for the Pope's visit to Turkey went ahead as usual.
The feeling inside the Vatican is that the storm aroused by the Pope's remarks will be quickly forgotten, when seen in their correct context.
Yet ambassadors of Muslim countries accredited to the Vatican (of which there are more than a dozen) are under instruction from their governments to press home their dissatisfaction at the way the Pope's officials have tried to brush off criticism and defend the pontiff.
In another gesture of friendship to the Muslim world the Pope has announced the appointment of a French prelate, born in Morocco when that country was a French protectorate, as his new foreign minister in charge of Vatican diplomacy.
The prelate, Monsignor Dominique Mamberti has in recent years been the Vatican's ambassador or nuncio in Algeria, Sudan, Eritrea and Somalia - all nations with large Muslim populations.