08/18/2011 at 07:00 AM EDT
A jihadist has marked David Letterman for death and ordered followers to "cut the tongue of the lowly Jew and shut it forever."
The demand, part of a rant on the Shumukh al-Islam Web forum, claims the Late Show
host – who is Protestant – must be punished for joking about Al Qaeda leader Ilyas Kashmiri, killed during a U.S. strike in Pakistan.
Kashmiri had been named as a possible replacement for the late Osama bin Laden
The FBI is investigating the threat, according to reports. It is also said that the agency knows of no specific plot against Letterman, who has been informed of the threat nevertheless.
CBS's Late Show
is currently on hiatus, while a spokesman for Letterman's production company, Worldwide Pants, would not comment on the threat, reports New York's Daily News
also notes that the author of the rant, who calls himself Umar al-Basrawi, describes Letterman, 64, as "a sick Jew with defined features."
Last year, South Park
creators Matt Stone and Trey Parker faced threats after they depicted the Prophet Muhammad in a bear suit.
Zachary Chesser, who pleaded guilty to providing material support to a terrorist group and inciting violence against Stone and Parker, was sentenced to 25 years in prison.