ATLANTA -- The Homeland Security Department says it’s investigating a threat to Atlanta’s Georgia Dome and several other NFL stadiums. The government wants you to know – it does not think the threat is credible.

A web site is claiming that seven stadiums – including the Georgia Dome in Atlanta – will be hit with dirty bombs this weekend.

The warning, posted Oct. 12, was part of an ongoing Internet conversation titled "New Attack on America; Be Afraid."

The warning mentioned Atlanta, New York, Miami, Seattle, Houston, Oakland and Cleveland where games are scheduled this weekend.

The Homeland Security Department has alerted authorities in each of the cities, but says the threat is being viewed with “strong skepticism.”

An official tells Channel 2 – out of an abundance of caution, the FBI here called together various players in the law enforcement and security community locally to brief them. The officials says representatives of the Georgia Emergency Management Agency, State Homeland Security, the GBI, Atlanta Police, NFL Security and Georgia Dome officials met at the Atlanta FBI office, which also houses the Joint Terrorism Task Force.

NFL spokesman Greg Aiello said stadiums around the country, "...are very well protected through the comprehensive security procedures we have in place, including secure facility perimeters, pat-downs and bag searches."

Officials were made aware of the Web posting on Oct. 16. The threat was timed to be carried out on Sunday, Oct. 22, marking the final day in Mecca of Ramadan, the Islamic holy month.

"The death toll will approach 100,000 from the initial blasts and countless other fatalities will later occur as result from radioactive fallout," according to a copy of the posting that was obtained by The Associated Press.

The bombs, according to the posting, would be delivered to the stadiums in trucks. All but one of the stadiums - Atlanta - are open-air arenas, the posting noted, adding: "Due to the open air, the radiological fallout will destroy those not killed in the initial explosion."

Explosions would be nearly simultaneous, the posting said, with the cities specifically chosen in different time zones.

The posting said that al-Qaida would automatically be blamed for the attacks and predicted, "Later, through al-Jazeera."

The Atlanta Falcons are scheduled to play the Pittsburgh Steelers on Sunday.

Dave Lockett, the Communications Coordinator of the Pittsburgh Steelers, commented on the threat:

"The department of homeland security has judged that the threat is not credible. The National Football League believes its stadiums are well protected by the security measures that are currently in place."