ROME -- The Vatican sent diplomats to capitals of Muslim nations yesterday in an effort to contain the anger over Pope Benedict XVI's comments on Islam, as shadowy threats against the pontiff and Christianity multiplied.
Despite the pope's expression of regret Sunday, protests continued yesterday in the Muslim world. One Internet posting from a group identifying itself as made up of Islamists told the pope: "You and the West are doomed."
In some places, conciliatory voices were heard, but many Muslims said they remained dissatisfied with Benedict's statement Sunday because he said he was "deeply sorry" for the outrage his speech last week provoked but did not apologize for the remarks themselves. Since the furor began, the pope has not acknowledged doing anything wrong or making a mistake.
In the speech last week before a gathering of academics at Germany's University of Regensburg, where Pope Benedict was a theology professor in the 1970s, the pope quoted a 14th-century Byzantine emperor who regarded some of the Prophet Muhammad's teachings as "evil and inhuman."
Web sites that have in the past been tied to Muslim extremists such as al-Qaida in Iraq posted threats yesterday against the pope and Rome, center of the Roman Catholic Church.
"We will conquer Rome like we conquered Constantinople," one message said, referring to the city - now Istanbul, Turkey - that was the capital of eastern Christendom until it fell to Muslim Ottomans in the 15th century.
The seriousness of the threats was difficult to determine, but Italian security forces have called for extra vigilance, and police surveillance reportedly has been stepped up at mosques, Arab-owned restaurants and call centers frequently used by Muslim immigrants.
Iran's supreme leader, Ayatollah Ali Khamenei, said the pope's speech was part of a "crusade against Islam" launched by President Bush.
Enraged protesters marched yesterday in the Indian and Pakistani-controlled sectors of Kashmir, and in Indonesia, the world's largest Muslim country. In Basra, Iraq, they burned a papal effigy and flags of the United States, Germany and Israel.
"We got out today to express our anger," said Basra taxi driver Abdul-Ameer Abdul-Wahid, 41. "The pope should have calmed down the situation instead of complicating things by talking about Islam."
Most of the demonstrations, though passionate, have remained fairly small. Guards have been posted at Christian churches in Egypt and in the West Bank and Gaza Strip, where several churches have been firebombed in recent days.
An Italian nun was shot and killed Sunday in Somalia after a radical cleric there condemned the pope's speech. An Italian diplomat and his wife were killed yesterday in Morocco - which recalled its ambassador to the Holy See in protest of the pope's remarks - but Italian officials said that case appeared to have been a robbery gone wrong.
"It is tragic that the reactions of the offended Islamists have translated into exactly the kind of violence that [the pope] was attempting to exorcise," commentator Gian Enrico Rusconi, a political scientist at the University of Turin, wrote on the front page of Italy's La Stampa newspaper.
The pope made no public comments yesterday and is next expected to address pilgrims during his weekly audience in St. Peter's Square tomorrow.
Cardinal Camillo Ruini, the influential auxiliary bishop of Rome and president of the Italian Bishops' Conference, said yesterday that the pope's comments had been distorted and manipulated, shouldering him with "responsibilities that he absolutely does not have and errors that he has not committed."
The Vatican's newspaper L'Osservatore Romano published the pope's expression of regret on its front page yesterday, in Italian, French, English and - highlighted in the center - in Arabic.
The pope's secretary of state, Cardinal Tarcisio Bertone, who took office Friday, said the Holy See's nuncios, the ambassadors who represent the Vatican abroad, will meet with government and religious leaders in Muslim countries to attempt to clarify the speech and its context.
Turkish and Vatican officials said Pope Benedict is still scheduled to visit Turkey, a Muslim country, in November.
Tracy Wilkinson writes for the Los Angeles Times.