The message was posted on an Islamist Web site and has not been determined to be authentic, CNN reports. The audio is in Arabic with English subtitles against a background of a photo of bin Laden.
Using the title "Fight on, Champions of Somalia," the message attacks Sheikh Sharif Sheikh Ahmed, founder of the Union of Islamic Courts and now president of the unity government in Somalia, as a turncoat.
Somalis are told that Ahmed should be "dethroned, fought and removed with armed force." Somalia is involved in a war between "Islam and the international crusade," bin Laden says.
Ahmed was ousted by Ethiopian troops who came to Somalia to support the western-backed "interim government." He was elected president on Jan. 31 by a group of Somali leaders meeting outside the country.
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