The FBI in Milwaukee has interviewed a young man from Wisconsin who has been associated with threats posted on the Internet, saying that a "dirty" bomb attack would take place during NFL games this weekend.
Law enforcement officials maintain that the threat is not credible.
"An individual has come forward and provided information about the posting of the threat against the NFL stadiums. The U.S. Government still believes this threat is non-credible. As this is an ongoing matter, we will not provide any additional information at this time," Richard K. Ruminski, FBI special agent in charge of the FBI Milwaukee field office, said in a statement.
On Wednesday, the Department of Homeland Security notified the NFL and authorities in New York, Miami, Atlanta, Seattle, Houston, Oakland, Calif., and Cleveland about the online threats.
Last week, officials said, a Web site said that truck bombs would be detonated at NFL games in New York, Miami, Atlanta, Seattle, Houston, Oakland and Cleveland.
Have Fun, Fans -- Despite the Scary Chatter
While FBI and Homeland Security officials emphasize this threat has no credibility, fans coming to a number of NFL stadiums will likely see enhanced security.
On Sunday, teams armed with radiation detection devices will sweep some stadiums checking for radiological or "dirty" bombs. And all entrances and parking areas will be monitored.
The government continues to receive intelligence from overseas that al Qaeda wants to hit the United States with a radiation attack, but FBI and Homeland Security officials are extremely skeptical.
They say the Web site that made the claim is based in the United States and comes from a company in Troy, N.Y., called Voxel Dot Net, which has no known ties to Islamic radicals.
On Wednesday night, the NFL issued a statement saying federal officials had told it, "The threat is not credible. Our stadiums are very well protected through the comprehensive security procedures we have in place, including secure facility perimeters, pat-downs, and bag searches."
So why issue a bulletin in the first place?
Police officials say in the post-Sept. 11, 2001, world virtually all threats are passed along.
Law enforcement officials advise fans to be vigilante, go to the games, and have a good time this weekend -- despite all the scary talk.