NAIROBI, Nov 26 (Reuters) - A U.S. warning of possible suicide attacks in Kenya and Ethiopia was prompted by the discovery of two letters signed by Somalia's most influential hardline Islamist leader, a Kenyan newspaper said on Sunday. Washington issued its warning to U.S. citizens on Nov. 2, in response to what it said were "terrorist threats emanating from extremist elements within Somalia". But a State Department spokesman gave no details on how those threats were presented. The Sunday Nation newspaper said it had obtained two letters purportedly signed by Sheikh Hassan Dahir Aweys, who appears on U.S. and U.N. terrorism lists, but it could not establish the authenticity of the documents. The newspaper said the letters called for the assassination of 17 prominent Kenyans and Somalis, an uprising by ethnic groups in Kenya and Ethiopia and for Shabab militia fighters to mass along the Kenya-Somali border. "The letters made specific threats against public targets in Ethiopia and Kenya and called for suicide attacks," said U.S. embassy spokeswoman in Nairobi Jennifer Barnes, adding that the letters led to Washington's advisory. U.S. embassies in Kenya and Tanzania were the target of truck bombs in 1998 that killed more than 200 people. Kenya has in the past expressed concerns that one of the alleged masterminds of the attack was sighted in the Somali capital Mogadishu and may be operating inside Kenya. The U.S. warning came two weeks after Somalia's interim president, Abdullahi Yusuf, addressed a meeting of U.S., European and African diplomats in which he cited a document, described as an order by Aweys approving both his and Prime Minister Ali Mohamed Gedi's assassination. A diplomat who follows Somalia said the letters quoted in the Nation appeared to be the same ones that were passed around the International Contact Group meeting in Nairobi last month. "We don't believe them," the diplomat said, referring to the letters. The leaked documents have surfaced amid increasingly belligerent rhetoric and heightened fears that a standoff between the interim government and rival Islamists may spiral into a regional war, sucking in neighbouring countries.
