The health of terrorist cleric Omar Abdel-Rahman, the so-called Blind Sheik, is deteriorating - renewing fears that his death in prison could trigger an attack on the United States, officials said Thursday. There is no credible indication that an attack on the US is imminent, said several law enforcement officials who spoke on condition of anonymity because of the sensitive nature of the situation. In a two-page bulletin, dated Dec. 8, the Federal Bureau of Investigation reported to federal intelligence officials that Rahman was rushed from prison to a Missouri hospital two days earlier for a blood transfusion. There, doctors discovered a tumor on Rahman's liver, according to the bulletin, which was described to The Associated Press by a law enforcement official. But US Bureau of Prisons spokeswoman Tracy Billingsley said Rahman's condition has stabilized, and he has since been moved back to prison.