BAGHDAD (Reuters) - U.S. forces say they have intercepted a letter intended for Abu Musab al-Zarqawi, the Jordanian militant who is the most wanted man in Iraq. They say the letter was sent by a man calling himself Abu Asim al-Qusaymi al-Yemeni, a member of al Qaeda in Iraq -- Zarqawi's group. It was intercepted on April 28th. In a statement on Tuesday, the U.S. military said unnamed analysts had determined the letter, addressed to "the Sheikh," was intended for Zarqawi because "many of his close followers refer to him as 'the Sheikh." "Sheikh" is a very common form of address in Arabic that can either refer to a tribal elder or a religious authority. The U.S. military said the letter, dated April 27th, praises the sheikh for being "a thorn in the mouth of the Americans," but also addresses low morale among Zarqawi's followers and weakening support for Jihad, or Holy war. In its statement, the military said the letter admonishes the sheikh for "abandoning his followers since Falluja," where U.S. forces drove out militants in a furious assault in November last year. However, it was not clear from the translation of the letter provided that the writer was admonishing the person he was writing to.