WASHINGTON – Police carrying semiautomatic rifles patrolled the grounds of the Capitol on Thursday, and the government warned key industries and utilities to beware of employees who might have been planted by Al Qaeda or other terrorist groups.
The security measures were the latest to emerge since the nation went on high alert for possible terrorist attacks last week. The orange level is the second-highest in a five-point, color-coded scale that would be topped only by a red alert that meant an attack was imminent or under way.
There are no plans to raise the threat level, Justice Department officials said. U.S. counterterrorism officials said they are continuing to gather intelligence but have no specific information as to targets or methods for a terrorist strike.
Authorities have said they are worried about attacks timed to coincide with the hajj, a Muslim holy period that ended Thursday, or the beginning of a war with Iraq.
Tension in the capital has risen, underscored by the officers carrying rifles in the Capitol complex and the deployment of antiaircraft missile batteries around the city. Other steps were being taken outside public notice. "They will be seen, they will not be seen. Some will never be known, but took place," White House spokesman Ari Fleischer said.
The FBI and the National Infrastructure Protection Center issued a bulletin Wednesday to companies involved in such industries as telecommunications, energy, and banking and finance, as well as operators of water systems and electric utilities, law enforcement agencies and emergency services.
Officials believe Al Qaeda could target these entities with chemical, biological or radiological attacks. Such an attack, officials say, could prompt terror and mass casualties and also disrupt the regional or national economy.
Of particular concern is the "dirty bomb," a crude, easy-to-make device that would spew radioactive material over a wide area.
Industry officials should check out their employees in an effort to root out any terrorists who may have been working there for years, waiting for the signal to strike. Al Qaeda's mode of operation is patience, sometimes taking years to plan an attack -- as it did for those that occurred on Sept. 11, 2001.
"Operatives will likely research potential targets extensively prior to an attack," the bulletin said. "Planning may begin months or years before an actual terrorist attack."
In addition, the warning said officials should check Internet sites describing their facilities and "consider how that information might assist terrorists interested in planning an attack."
Company officials should make sure that security routines are varied and think back to any unusual incidents in the past that might indicate their facility was under surveillance or being targeted.
"We have entered what may very well prove to be the most dangerous security environment the world has known," Defense Secretary Donald H. Rumsfeld told the Senate Armed Services Committee on Thursday.
Attorney General John Ashcroft said in an interview Wednesday that the Justice Department may ask Congress to change a law requiring public release of "worst-case scenarios" that describe what might happen in a disaster involving heavy industry, nuclear plants, dams and the like.
"I don't know that we ought to provide aspiring terrorists with copies of worst-case scenarios that anticipate what the consequence would be and how they ought to structure an attack," Ashcroft said.
For those in the private sector who might be faced with or respond to an attack, the bulletin recommends reading the Chemical, Biological and Radiological Incident handbook available on the CIA Internet site. This handbook describes warning signs of chemical, biological and radiation attacks and steps individuals can take to protect themselves.
The FBI bulletin urges anyone who comes in contact with a suspect substance to "cover their mouths with a cloth while leaving the area, avoid touching surfaces and wash their hands thoroughly."