DUBAI (Reuters) - Al Qaeda leader Osama bin Laden threatened the European Union with grave punishment on Wednesday for publication of cartoons mocking Islam’s Prophet Mohammad.

In an audio recording posted on the Internet coinciding with the birthday of Islam’s founder, bin Laden said the drawings, considered offensive by Muslims, were part of a “new crusade” in which Pope Benedict was involved.

“Your publications of these drawings -- part of a new crusade in which the Pope of the Vatican had a significant role -- is a confirmation from you that the war continues,” said the Saudi-born militant leader, addressing “those who are wise at the European Union”.

You are “testing Muslims ... the answer will be what you shall see and not what you hear.”

It was bin Laden’s first message since November 29 when he urged Europe to end participation with U.S. forces in Afghanistan.

The message, produced by al Qaeda media arm As-Sahab in the lunar month which ended on March 8, carried an animation of a spear piercing through a red map of Europe with blood splashing as its tip penetrated the surface.

It also carried what appeared to be an old picture of bin Laden firing an assault rifle. The message also coincides with the fifth anniversary of the U.S.-led invasion of Iraq.

Michael Scheuer, a former CIA bin Laden tracker, said: “It’s not a coincidence that it was released on the day that is observed in the Muslim world as the Prophet’s birthday.”

He added: “It’s only ominous when he says ‘don’t listen to our words, watch for our actions’ ... that means they clearly are intending to attack in Europe.”

THREAT AGAINST EUROPE

The U.S.-based IntelCenter, a terrorism monitoring firm, said the message was “a clear threat against EU member countries and an indicator of a possible upcoming significant attack, however, it is unclear in exactly what timeframe it may occur.”

Bin Laden said the publication of the cartoons was a graver offence than the “bombing of modest villages that collapsed over our women children”, in reference to U.S.-led invasion of Iraq and Afghanistan with European participation. “This is the bigger catastrophe ... for which the punishment is graver.”

“Animosity among people is very old but wise people ... have always been keen on maintaining the manners of disagreement and the ethics of fighting ... but you have abandoned many of these ethics although you use them as slogans,” he said.

Bin Laden said Europe was intentionally targeting Muslim women and children at the behest of their “unjust ally who is close to departing the White house”.

He said “brutality” had not defeated Muslims and made them determined to “avenge our folk and eject the invaders from out countries.”

A U.S. counterterrorism official said the authenticity of the recording was under examination but added it was in line with “al Qaeda’s ongoing propaganda effort.”

The cartoons were first published by the Danish daily Jyllands-Posten in September 2005 but a furor erupted only after other newspapers reprinted them in 2006.

Osama bin Laden sits during an interview with Pakistani journalist Hamid Mir (not pictured) in an image supplied by the respected Dawn newspaper November 10, 2001. REUTERS/Hamid Mir/Editor/Ausaf Newspaper for Daily Dawn

CARTOONS

On February 13 several Danish newspapers published one of the cartoons in solidarity with the cartoonist after three men were arrested on suspicion of plans to kill him.

One of the cartoons shows a man described as Islam’s prophet wearing a turban with a bomb in its folds.

At least 50 people were killed in the protests against the cartoons, which Muslims say are an affront to Islam. Newspapers which printed them say they are defending media freedom.

Sajjan Gohel of the Asia-Pacific Foundation, a London-based security think-tank, said the message did not necessarily signal an imminent attack in Europe but was a “statement of intent”.

“A bin Laden message doesn’t necessitate countries in Europe increasing their threat levels. The reason why they would do that is based on actual intelligence,” he said.

“But when Osama bin Laden talks, people listen -- his supporters and constituents throughout the world are motivated by his words and want to turn them into action... Europe has become the battleground for al Qaeda.”

European countries singled out by al Qaeda in the past include Britain, Spain, Italy and Denmark. The new message is likely to cause particular concern to Denmark.

Bin Laden’s attempt to stoke Christian-Muslim tensions, by evoking the crusades, also comes as the Netherlands braces for the expected release on March 28 of a film about Islam by a right-wing politician who has called the Koran a “fascist” book.

Tensions over the film prompted the Dutch to raise their terrorism threat level earlier this month.

Bin Laden, the man behind the September 11 attacks on U.S. cities, issued several messages late in 2007 after a hiatus of well over a year raised speculation that he might be dead.

Bin Laden, believed to be in remote areas between Pakistan and Afghanistan, often marks significant events with messages.

On September 7 bin Laden appeared in a video marking the sixth anniversary of the September 11 attacks and said the United States remained vulnerable despite its economic and military power.