Sources tell CBS News that the bulletin is simply a reminder that Rahman has made that type of "general threat" in the past. There is no intelligence suggesting any attack is planned.
One security official told CBS News that this bulletin is the equivalent of saying "there are bad guys out there who still want to hit us."
In a two-page bulletin, dated Dec. 8, the FBI reported to federal intelligence officials that Abdel-Rahman had been 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 U.S. Bureau of Prisons spokeswoman Tracy Billingsley said Abdel-Rahman's condition had stabilized, and he has since been moved back to prison.
"His condition has improved," Billingsley said.
Officials said the bulletin served merely as a reminder that Abdel-Rahman had called for retaliation by terror sympathizers if he died in prison. It cited a May 1998 news conference in which al Qaeda members distributed his last will and testament, in which Abdel-Rahman pleaded for followers to "extract the most violent revenge" should he die in U.S. custody.
The FBI did not have immediate comment on Thursday.
In a video in September marking the fifth anniversary of the Sept. 11 attacks, al Qaeda's No. 2 man, Ayman al-Zawahri, cited the continuing imprisonment of the sheik.
"I call on every Muslim to make use of every opportunity afforded him to take revenge on America for its imprisonment of Sheik Omar Abdel-Rahman," he said.
Abdel-Rahman was sentenced to life in prison after his 1995 conviction for his advisory role in a plot to blow up New York landmarks, including the United Nations.
His health has deteriorated in recent years, and he was transferred in September 2003 from the federal Supermax prison in Colorado, where the country's most notorious inmates are held, to the U.S. Medical Center for Prisons in Springfield, Mo. Prisons officials have said Abdel-Rahman has suffered from diabetes, which has threatened the loss of his limbs.
Terror expert Dia'a Rashwan said Abdel-Rahman's death would not be likely to incite huge attacks in the United States because he is closer to an Egyptian militant group than to al Qaeda and "does not enjoy such a status on international level."
Instead, "I expect some small and easy violent acts and attacks, especially in Afghanistan, in retaliation to his death and to keep the name of Omar Abdel-Rahman as a martyr," said Rashwan, an expert at the Al-Ahram Center for Political and Strategic Studies in Cairo, Egypt.