People with supposed links to terrorist groups have accessed a Web site about stadiums worldwide, downloading images of at least St. Louis' Edward Jones Dome and Indianapolis' RCA Dome, an FBI official said Wednesday.

"There's no specific threat," said Bill Eubanks, head of St. Louis' FBI office. "They just simply accessed the Web site."

Eubanks said a "very vague" FBI intelligence bulletin in recent days to law-enforcement agencies nationwide, warned of government knowledge of individuals with "ties" to terrorist groups downloading images of certain U.S. stadiums pictured on www.worldstadiums.com. At least two of those stadiums included the domed venues in St. Louis and Indianapolis, he said.

While downplaying the bulletin, Eubanks said the FBI has coordinated security plans with St. Louis police, and representatives of the National Football League, the Edward Jones Dome and the St. Louis Rams, who play at the dome.

"I'm sure security at the stadium is taking extra precautions," Eubanks said.

The St. Louis and Indianapolis stadiums were to be closed Thursday for the holiday, officials said.

Bruce Sommer, director of the America's Center convention complex that includes the Edward Jones Dome, said he learned of the FBI memo Monday from the NFL. Since then, he said, the complex's security workers and other employees have been told "to be terribly vigilant about what they see and who they see," reporting anything suspicious.

"Generally, that's about all we can do," Sommer said. "That's (standard procedure) from now on, and that's the way it will always be."

Without elaborating, Sommer said the complex's security already had been enhanced since the Sept. 11 terrorist attacks.

"There's no reason for anyone to alter how they do business with us or attend events," he said. In conveying the FBI memo, he added, "officials have been clear that it was not a threat, not even a perceived or implied threat."

"There's no reason to believe anything is going to happen to this facility," he said.

Police Chief Joe Mokwa said he did not view the FBI memo as "an imminent threat," but only as "one aspect of a myriad of clues that we are provided almost daily."

"It's noteworthy and needs to be attended to, but it's nothing that should prevent the people of St. Louis from attending events at the dome. We have to put it in perspective," Mokwa said.

In post-Sept. 11 America, he added, "it's an unfortunate set of circumstances that our country and community always are going to be deluged with portions of information like this."

Eubanks said there was little cause for alarm.

"The worst thing we can do is buckle under terrorism. That's what (terrorists) want us to do, thinking they can disrupt our lives," he said. "But certainly we should have caution and awareness."

Doug Garrison, an FBI spokesman in Indianapolis, said the agency alerted state and local law enforcers about the stadium matter, though he also said there was no indication of a credible threat to any specific site.