Police were ordered to guard the tomb of medieval poet Dante Alighieri following a bomb threat from a purported Islamic group angered by a reference in "The Divine Comedy" that the prophet Mohammed suffers in hell.

While declaring the threat was probably a joke in poor taste, Ravenna Mayor Mauro Dragoni said Sunday that police were standing watch on Dante's tomb after a group calling itself the Guardians of the Revolution threatened to blow it up. Dante died in Ravenna in 1321.The threat, sent in a letter to a local newspaper, was revealed shortly after a bookstore in Padua displaying the Iranian-condemned novel "The Satanic Verses" was damaged in an arson fire.

officials said.

The group expressed anger at Dante's depiction of Mohammed, the founder of Islam, as tormented and suffering in the ninth circle of hell in his poetic masterpiece, "The Divine Comedy."