The Washington metropolitan area has become "the number one target in the world" for possible terrorist attacks, a top FBI expert on domestic terrorism warned a group of local law enforcement officials last night, adding that the region's safety and medical personnel must be ready to respond swiftly and work together to minimize deaths after such a disaster.

Jim Rice, special agent in charge of the FBI's national capital domestic response team, said downtown Washington receives three to six suspicious packages a day that must be handled carefully by experts trained to detect explosives as well as chemical and biological weapons. He also said the FBI has investigated 225 new cases of possible chemical and biological terrorism nationwide this year, an increase over the 181 new investigations that the bureau conducted all of last year.

Speaking to about 100 police and fire officials from the District, Maryland and Virginia, both Rice and James C. Carter, head of the FBI's Washington field office, said the nation's tough stance against terrorism has angered terrorists around the world, who now view the nation's capital as a primary target.

"Everyone in the world has looked at us through the cross hairs at some time," Rice said.

Carter said the question about terrorism in the Washington area is not whether, but when. By "going after terrorists," he said, the United States has found many enemies.

Rice said he heads a new specially trained 50-person team in the FBI's Washington field office to lead counterterrorism efforts in the event of an attack. He also said the FBI was focusing heavily on trying to detect and prevent domestic terrorist acts in the region.

Rice was asked what precautions the FBI has taken to protect the area's Metro system by a questioner who mentioned the sarin gas attack on the Tokyo subway in the mid-1990s. Rice said FBI policies prohibited him from commenting specifically, but he said he has reviewed contingency and emergency plans with various regional officials, including those who work for Metro.

Rice said the bureau increased the size of the special counterterrorism unit in recent years significantly after a conversation between Attorney General Janet Reno and Carter. Last night, Carter said the FBI is prepared, in the event of a biological or chemical attack in Washington, to inform residents through the news media about what steps must be taken to contain the casualties.

Earlier yesterday, Rice conducted a seminar at George Mason University on how local law enforcement agencies should respond to terrorism incidents. He said last night that decontamination units have been established at certain area medical facilities to counter the potentially deadly effects of biological weapons. And he said the FBI would inform the public about where to go for emergency medical assistance.

"We're developing an aggressive media approach to these type of events," Carter said. "We are going to be very aggressive in getting information out."

During the session, Rice commanded the attention of everyone in the room by pulling substances out of jars and vials and declaring in staccato fashion, "This is anthrax. . . . This is bubonic plague. . . . This is cholera." Rice said he wanted the group to know what those substances looked like and then reassured them that the chemical agents he was displaying were "inert."

Although an official involved in organizing last night's session described it as "off the record," the FBI earlier said it was on the record and Rice agreed, saying afterward that he had not disclosed any "classified information."

Rice was asked about the potential terrorist threat on the Mall during the upcoming New Year's Eve celebration marking the turn of the century. Rice said the FBI was working on security for the event but that he did not regard the potential for terrorism that night as any different than at the annual July Fourth fireworks.

"Our biggest fear is a small device in a backpack," Rice said, adding that the FBI would use bomb-sniffing dogs to try to prevent anyone from hiding a small explosive on the Mall.

Rice said Jerusalem posed the likeliest terrorist target around New Year's because of radical terrorist groups that believe biblical references that the holy city is where the Apocalypse will begin.