WASHINGTON - Homeland Security Secretary Tom Ridge sought to calm jittery Americans Friday, saying they should be vigilant but there was no need "to start sealing the doors or windows" against terrorist threats.
After many people spent a week stocking up on duct tape and watched anti-aircraft missile launchers set up around their national capital, Ridge said preparation, not panic, is in order.
He also said officials don't have any conclusive intelligence where, when or how the terrorists could strike.
"I want to make something very, very clear at this point: We do not want individuals or families to start sealing their doors or their windows," Ridge told reporters at his headquarters.
Earlier this week, federal officials recommended Americans put together emergency supply kits as a precaution - for terrorist attack or disaster. Two items suggested for that kit were duct tape and plastic sheeting, enough to seal a house or rooms from any hazardous materials terrorists could put in the air.
A week after increasing the terrorist alert level from yellow to "high risk" orange, President Bush said that decision had been a "stark reminder of the era that we're in, that we're at war and the war goes on."
Bush also unveiled plans to unify counterterrorism efforts, locating FBI and CIA work at a single center though the agencies' lines of authority would remain distinct. "We're doing everything in our power to make sure the homeland is secure," the president said at the FBI.
Ridge said there were no plans to increase or lower the alert level.
Officials, speaking privately, acknowledged that polygraphs suggested terrorist suspects had fabricated some of the information that led to the latest increase. Other officials said the intelligence that led to the increase came from a far larger base of reliable sources.
One official said federal authorities have identified between 20 and 40 people in the United States who trained in al-Qaida camps in Afghanistan. Of those, fewer than a dozen are believed to have had recent contact with al-Qaida operatives overseas, this official said.
Authorities are keeping tabs on roughly 600 al-Qaida sympathizers in this country, said the official, who cautioned that there may be many more who are unknown to law enforcement authorities.
Also, U.S. officials said technical analysis of a recent audio message from Osama bin Laden declaring solidarity with Iraqis has determined the tape to be "almost certainly" authentic.