Sheik Abdel Omar Rahmans helse er blitt dårligere, og amerikanske myndigheter frykter hva som skjer hvis han dør i fengsel.

Abdel-Rahman had called for retaliation by terror sympathizers if he died in prison. It cited a May 1998 news conference in which al-Qaida 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-Qaida’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 City landmarks, including the United Nations.