Police across Italy have been ordered to raise security at potential Catholic targets, after Pope Benedict XVI angered Muslims last week with remarks against Islam, reported The Associated Press.

The Pope said he was “deeply sorry” for having offended Muslims with is remarks, which he said came from a text that did not even reflect his personal opinion.

Security was higher than usual at the papal palace in Castelgandolfo yesterday, where the Pope gave his usual message and prayed the Angelus with the faithful. Sharpshooters kept watch from a balcony while police dressed like tourists monitored the crowd.

However, at the Vatican, no additional security measures could be seen as tourists strolled across St. Peter's Square, reported the AP.

Despite the Pope's apology, protests and violence persisted across the Muslim world. Two more churches were set ablaze in the West Bank. Two armed Iraqi groups also threatened the Vatican with reprisals, in statements posted yesterday on the Internet, reported the Khaleej Times Sept. 17.

“Know that the soldiers of Mohammed will come sooner or later to shake your throne and the foundations of your state,” said the group Asaeb Al Iraq Al Jihadiya (League of Jihadists in Iraq), which often posts online video footage including attacks on American targets in the country.

It called on “all Muslims” to retaliate against “Christians and Jews, whose religions are hostile to Islam.”

Jaish Al Mujahedeen (the Mujahedeen’s Army) threatened on Saturday to strike at Rome and the Vatican. The group posted another statement issued on Sunday, saying that the group’s reply “will come with deeds, not words.”

Meanwhile a radical Islamic leader in London, England called for the Pope to be executed.  Anjem Choudary, who spoke at a demonstration he organized in front of London’s Catholic cathedral, said “Whoever insults the message of Mohammed is going to be subject to capital punishment.”

He also insinuated that perhaps Italian Muslims might want to carry out the death sentence saying, “there may be people in Italy or other parts of the world who would carry that out.”

"I think that warning needs to be understood by all people who want to insult Islam and want to insult the prophet of Islam."