Letters threatening biowarfare sent to Stephen Colbert, Jon Stewart

New York City-based Comedy Central hosts Stephen Colbert and Jon Stewart received letters this week that contained language threatening biological attacks on United States senators.

The messages, which were anti-Wall Street and anti-establishment in tone, warned that 10 out of 100 senators would receive letters containing lethal pathogens, the Hollywood Reporter reports.

In addition to "The Colbert Report" and "The Daily Show," media organizations such as the Los Angeles Times, the New York Times and National Public Radio also received the senator-threatening, rant-laden letters that were signed "the MIB." Unlike letters that had also been sent to several government offices this week, the letters to the media organizations did not contain a suspicious, but harmless, powder.

"So far, none of the letters have contained a hazardous substance," Jason Pack, an FBI special agent, said, according to the Associated Press. "We are working with those law enforcement agencies affected to determine if the mailings are related. We take these matters seriously and will investigate fully."

Representatives for Comedy Central have yet to respond to a request for comment.

House Speaker John Boehner was one of the politicians targeted by the letters containing the powdery substance. The politicians were targeted at their home and district offices.