Even before bombs began falling on Baghdad last night, authorities across the state stepped up searches of cars at the airport and trucks on the highways, amid fears that the war could trigger terrorist acts around the nation.
Maryland State Police and local law enforcement increased security at nuclear power plants, drinking water sources and important "symbolic" sites, said Quentin Banks, a spokesman for the Maryland Emergency Management Agency.
Traffic on Interstate 95 was slowed as trucks were inspected by Maryland Transportation Authority Police at Caton Avenue. Commuters experienced delays as a result.
Police did not find any suspicious materials yesterday, said Cpl. Greg Prioleau, a Maryland Transportation Authority Police spokesman.
The agency stopped trucks weighing more than 5 tons along I-95 for careful searches.
Police normally inspect trucks at random after they pass through the Fort McHenry Tunnel near the toll roads, but police shifted the inspections to Caton Avenue so vehicles would be examined before they entered the tunnel on northbound I-95.
The searches led to long lines of trucks, slowing traffic headed into the city. Most drivers reported slight delays, but there was a significant backup about 10 a.m. when traffic piled up for nearly a mile, Prioleau said. To relieve congestion, police shifted to spot checks until the backup cleared, he said.
Police also searched cars at Baltimore-Washington International Airport.
"We don't typically do vehicle searches, but given the orange alert, we are doing them today," said airport spokeswoman Cheryl Carley-Stewart.
In Baltimore last night, Mayor Martin O'Malley activated the city's emergency operations center, where officials of the police, fire and public works departments stood at the ready as a precaution as the war began.
Baltimore County Executive James T. Smith Jr. said the start of the war will not have an obvious immediate impact in the county because officials there have been on heightened watch since Monday, when Homeland Security Director Tom Ridge elevated the nation's terror alert level from yellow to orange.
Since then, county police have stepped up monitoring of municipal buildings, synagogues, mosques and important infrastructure, Smith said.
"People are certainly going to see more security; certainly there's going to be more information coming to them about what they should do and what maybe they shouldn't do, but frankly, other than some intensification, some going to a higher level, we're really basically on the watch now and we have been," Smith said.
Cpl. Jim Elliott of the Baltimore County Police said the department planned some additional security measures for the start of the war, and a few commanders met last night to begin implementing them. He would not say what they were.
As in the previous two nights, extra Maryland Transportation Authority police patrolled the Bay Bridge last night, Cpl. Barry Poindexter said. The number of officers on duty had been increased Monday when the alert was heightened.
Anne Arundel County police also maintained extra patrols as word of war spread. "They're probably finding out the same way you and I are, by radio and television," Cpl. Joe Hatcher said. "Everything is status quo."
At the U.S. Naval Academy, a spokesman declined to comment on the military school's security procedures. He said he didn't know how today would unfold on the campus. "I don't want to comment," Cmdr. Bill Spann said. "I don't have a crystal ball."
In Harford County, Sgt. Daniel Fairburn of the Bel Air barracks of the Maryland State Police said troopers there increased patrol checks and took other steps to increase security after the threat level increased Monday.
"If [the threat level] does change, our captain will be notified and certain steps will take place," Fairburn said. "I have been in touch with the captain, and we're on standby."
And in Carroll, the Westminster barracks of the state police remained at Code Orange. At the Carroll County Emergency Operations Center, the 90 minutes before the start of the bombing and the president's speech were eerily quiet, said Mike Munshauer, shift supervisor.
"We were all remarking on how quiet it was, with little activity," Munshauer said. "I guess most people were at home watching for news on their televisions."
Iraqi leader Saddam Hussein warned this week that if Iraq is attacked, it will take the war anywhere in the world "wherever there is sky, land or water."
A recent statement from Osama bin Laden, the Saudi-born leader of al-Qaida, declared solidarity with Iraqis.
Experts say Maryland presents a wide range of potential targets - from a busy seaport to important military installations.
But experts disagree on whether terrorists, if they strike, are more likely to use biological weapons, home-made bombs, Molotov cocktails or sniper fire.
And no one knows whether the targets will be cafes or malls in Washington or New York, military contractors in Maryland, or corporate headquarters elsewhere in the United States.
Budget constraints have meant that the state and local jurisdictions have not hired enough public health workers to manage a bioterrorism crisis, said Dr. Tara J. O'Toole, director of the Johns Hopkins University Center for Civilian Biodefense Strategies.
Local authorities still need to devise a better system to help doctors communicate with each other during an outbreak, she said.
And local officials need to figure out a faster and more efficient way to distribute vaccines and antibiotics to health care workers, so they can treat a possible influx of infected people, O'Toole said: "We should have done more, but at this point we need to look ahead."
The Coast Guard is in the process of calling up about 3,000 reservists - more than a third of its total reserves - on the Atlantic coast.
"The orange alert means additional security measures within the ports and waterways; what that will mean is that the Coast Guard will be more visible and vigilant," said Lt. Cmdr. Brendan McTherson, a spokesman for the Atlantic Area Command in Portsmouth, Va.
Craig Nesbit, spokesman for Exelon Corp.'s nuclear operations, which runs the Peach Bottom nuclear power plant in York County, Pa., said that company has tightened security.
"There are certain things that we do each time the level is elevated," he said. Access to the plant becomes more restricted, with some contract workers and nonessential employees told to stay away. Some projects at the plant might be postponed as well, he said.
Security also has been increased at the Calvert Cliffs nuclear power plant, on the Chesapeake Bay in Lusby, according to Ellen Kane, spokeswoman for Constellation Energy Group, which runs the facility in Southern Maryland. She refused to describe those precautions even in general, citing the need to keep security measures confidential.
Staff writers Ryan Davis, Andrew A. Green, Mary Gail hare, Jason Song and Timothy B. Wheeler and the Associated Press contributed to this article.