Muslim religious leaders have accused Pope Benedict XVI of quoting anti-Islamic remarks during a speech at a German university this week.
The Pope's comments came on a visit to Germany
Questioning the concept of holy war, he quoted a 14th-Century Christian emperor who said Muhammad had brought the world only "evil and inhuman" things.
A senior Pakistani Islamic scholar, Javed Ahmed Gamdi, said jihad was not about spreading Islam with the sword.
Turkey's top religious official asked for an apology for the "hostile" words.
In Indian-administered Kashmir, police seized copies of newspapers which reported the Pope's comments to prevent any tension.
A Vatican spokesman, Father Frederico Lombardi, said he did not believe the Pope's comments were meant as a harsh criticism of Islam.
In his speech at Regensburg University, the German-born pontiff explored the historical and philosophical differences between Islam and Christianity and the relationship between violence and faith.
Stressing that they were not his own words, he quoted Emperor Manual II Paleologos of the Byzantine Empire, the Orthodox Christian empire which had its capital in what is now the Turkish city of Istanbul.
The emperors words were, he said: "Show me just what Muhammad brought that was new and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached."
Benedict said "I quote" twice to stress the words were not his and added that violence was "incompatible with the nature of God and the nature of the soul".
The Pope is due to visit Turkey in November and the Turkish response was swift and strong, the BBC's Sarah Rainsford reports from Istanbul.
Religious leader Ali Bardakoglu said the Pope's comments represented what he called an "abhorrent, hostile and prejudiced point of view".
Whilst Muslims might express their criticism of Islam and of Christianity, he argued, they would never defame the Holy Bible or Jesus Christ.
He said he hoped the Pope's speech did not reflect "hatred in his heart" against Islam.
Many Turks see Benedict as a Turkophobe and commentators call his words just before the holy month of Ramadan "ill-timed and ill-conceived", our correspondent adds.