Trey Parker, left, and Matt Stone revealed that Comedy Central had removed a speech by Kyle, one of South Park's main characters, about intimidation and fear at the end of this week's episode. ((Ethan Miller/Getty Images) )

The producers of South Park say Comedy Central removed a speech about intimidation and fear from their show after a radical Muslim group warned they could be killed.

The character Kyle's words toward the end of Wednesday's episode were bleeped out.

Producers Trey Parker and Matt Stone, who created the satirical animated series, say the character does not mention the Prophet Muhammad.

The group Revolution Muslim had complained that South Park had insulted its prophet by depicting him in a bear costume in last week's episode.

The group didn't explictly threaten the producers, but warned they could wind up like Dutch filmmaker Theo van Gogh, who was killed by a Muslim extremist. The group printed Stone and Parker's work address on its website.

More than 30 seconds worth of dialogue were covered up in the episode.