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LONDON, March 20 Reuters) - Al Qaeda leader Osama bin Laden called on Palestinians to use "iron and fire" to end an Israeli blockade of the Gaza Strip and liberate their country.

In an audiotape broadcast by the Qatar-based Al Jazeera satellite channel on Thursday, bin Laden also urged Muslims to keep up the struggle against U.S. forces in Iraq as a way of "liberating Palestine".

"My speech is about the Gaza siege and the way to retrieve it and the rest of Palestine from the hands of the Zionist enemy," bin Laden said.

"Our enemies did not take it (Palestine) by negotiations and dialogue but with fire and iron. And this is the way to get it back."

The recording came one day after bin Laden issued an Internet statement threatening the European Union with grave punishment for the publication of cartoons mocking Islam's Prophet Mohammad.

It was not immediately possible to verify the authenticity of Thursday's recording. (Reporting by Sami Aboudi; Editing by Robert Woodward)

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