Al Qaeda leader Osama bin Laden threatened the EU with grave punishment over cartoons of 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 EU".

You are "testing Muslims... the answer will be what you shall see and not what you hear. May our mothers lose us to death if we did not rise in defence of the messenger of God..."

It is bin Laden's first message since November 29 when he urged Europe to end participation with US 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 US-led invasion of Iraq.