UPDATE 4-Vatican rejects bin Laden's "new crusade" charges

(Adds Vatican comment on Pope's security, Easter schedule)

By Philip Pullella

VATICAN CITY, March 20 (Reuters) - The Vatican rejected on Thursday accusations by al Qaeda leader Osama bin Laden that the publication of cartoons mocking the Prophet Mohammad was part of a "new crusade" involving Pope Benedict.

"These accusations are totally unfounded," chief Vatican spokesman Rev. Federico Lombardi said in response to an audio recording by bin Laden which was posted on the Internet to coincide with the birthday of the founder of Islam.

Italian security officials are examining the bin Laden message and its impact on the Pope. The Vatican said the Pontiff's heavy schedule of Easter celebrations this weekend would not be changed.

The Saudi-born militant leader said Europe would be punished for the cartoons, which were first published by a Danish paper in September 2005. The images ignited bloody unrest among Muslims when other newspapers around the world reprinted them the following year.

Last month several Danish newspapers republished one of the cartoons in solidarity with the cartoonist, after three men were arrested on suspicion of plans to kill him. This sparked fresh protests by Muslims.

"Your publications of these drawings -- part of a new crusade in which the Pope of the Vatican has a significant role -- is a confirmation from you that the war continues," said bin Laden, addressing "those who are wise at the European Union".

U.S. officials said the CIA was confident the voice was that of the fugitive leader of al Qaeda, blamed for the September 11, 2001, attacks on the United States.