On the waterways of Oregon, Coast Guard speedboats scanned riverbanks for any sign of something sinister.
And amid the skyscrapers of New York, where war came home one clear September day, helmeted tactical officers stood guard on Wall Street as a new war unfolded in the sand dunes and streets of Iraq.
The nation battened down under security not seen since the Sept. 11 attacks as U.S. forces attacked on Wednesday night.
The FBI Thursday issued a worldwide alert for Adnan G. El Shukrijumah, a Saudi national believed to be plotting terrorist attacks as part of al Qaeda. He was last seen in Miami before he disappeared. His current whereabouts are unknown.
"El Shukrijumah is possibly involved with al Qaeda terrorist activities and, if true, poses a serious threat to U.S. citizens and interests worldwide," the FBI said in a statement.
CBS News Correspondent Jim Stewart reports the FBI seems very interested in El Shukrijumah, although the Bureau implies it has nothing to do with the ongoing hostilities with Iraq. However, the FBI has been concerned for awhile that al Qaeda might use the start of the war in Iraq as a cover and launch new attacks in the United States.
Abraham told members of the Senate Armed Services Committee during a hearing that he couldn't go into details about intelligence reports concerning the plant, the nation's largest commercial nuclear power facility. But in response to a question by Sen. John McCain, R-Ariz., he acknowledged there were indications that it might have become a target for terrorist.
"Actions are being taken by all the appropriate agencies to address the concerns that have been raised," Abraham said.
Homeland Security Department chief Tom Ridge, testifying separately on Capitol Hill, said there had been no reports of incidents since the bombing of Iraq commenced Wednesday night.
He said there had been an additional layer of security in place around the country since Monday when the department raised the national terror alert to orange, indicating a high risk of attack. There are no immediate plans to change that alert level, he said.
The Washington Times reported Thursday that the government is seeing Iraqi "sleeper cells" that might have planned an attack on the plant.
The State Department Wednesday evening issued an updated worldwide caution, reports CBS News Correspondent Charles Wolfson, warning U.S. citizens abroad of the potential for anti-American violence. The threats include the possibility of attacks by terrorist groups, and notes that terrorists do not distinguish between official and civilian targets.
A separate warning was issued to caution all Americans in the Middle East and North Africa.
School officials in Washington's Maryland suburbs canceled field trips not only to the Nation's Capital, but also other East Coast cities.
Washington is the "safest place to be," countered Washington police chief Charles Ramsey, who added that there was "absolutely no reason" not to come to the nation's capital. Ramsey said he was comfortable with the security plans in place, and the only advice he had for anyone coming to the city Thursday was to bring an umbrella.
The Transportation Security Administration sent a security directive to airports and airlines Tuesday night, telling them to post more law enforcement officers in and around terminals and airport perimeters. Some airports were ordered to conduct random vehicle inspections. Some restricted parking in lots close to terminals.
Sen. Olympia Snowe, R-Maine, criticized the TSA for failing to communicate quickly with key law enforcement officials the last time a terrorism threat alert was raised. This time, her office checked and found the people most involved with homeland security had learned in advance about the Monday night decision to go to code orange, the second highest terror alert.
"It's getting better," said Snowe's spokesman, Davis Lackey. "They've worked through the initial delays."
The Coast Guard is now escorting ships into port and stepping up patrols of waterways. Four special maritime security units of 100 Coast Guardsmen each are in position in undisclosed ports.
Pipeline operators were advised by the Transportation Department to take a series of actions to protect the 2.3 million miles of pipe within the United States. At code orange, the pipeline industry has a checklist of 44 more things to do, such as posting security at critical points 24 hours a day.
The Federal Transit Administration, which has been conducting emergency forums with transit systems since Sept. 11, advises them to move cars and trash containers away from buildings, make sure their intruder alarms are working and disable baggage lockers.