Washington Goes Into High Alert : Security: FBI reportedly countered five possible terrorist attacks in U.S. since the invasion.

With the possibility of war only hours away, official and unofficial Washington went into a state of high alert Tuesday that was evidenced by tightened security, the laying of last-minute contingency plans and a palpable sense of foreboding.

Senior Justice Department officials said the FBI has countered more than five possible terrorist attacks against targets in the United States since Iraq invaded Kuwait in August.

“Some were plans headed off, some were individuals attempting to concoct plans--and who knows how serious they were,” one official said in a briefing at the Justice Department, where security measures have been intensified.

If fighting starts--”if the balloon goes up,” in military parlance--official word would be shot through diplomatic channels to world leaders. It would be conveyed in each country by the U.S. ambassador to the head of government.

Gen. Colin L. Powell, chairman of the Joint Chiefs of Staff, is charged with notifying each of his military counterparts in the multinational alliance against Iraq. Defense Secretary Dick Cheney also is believed to have a channel for notifying Washington’s North Atlantic Treaty Organization partners.

The law requires notification of only two congressional leaders--House Speaker Thomas S. Foley and Sen. Robert C. Byrd, president pro tempore of the Senate. However, the White House would probably get word quickly to other congressional leaders and ranking members of crucial committees. A spokesman for Foley said that the Speaker does not expect to get word until an attack is under way.

Most Americans are likely to hear it from television: The networks are planning 24-hour coverage of any hostilities.

In Washington, communication is all. Companies that sell electronic pagers reported a surge business from the military, defense contractors, government agencies and the news media--all of which wanted to be certain that they could contact critical employees in the event that fighting begins.

Debbie Caperna of Page Plus in Columbia, Md., said her firm has received one inquiry regarding the availability of large numbers of pagers for medical personnel who would be involved in treating wounded troops. Newsweek Bureau Chief Evan Thomas said his office had bought six, even though it faces deadlines only once a week.

“When you start buying beepers at a weekly, you know it’s serious,” Thomas said.

In recent days, he said, he has sensed a different mood and an abrupt end to the black humor that reporters bring to most major events. “People are a little stunned by how real this all is.”

It was clear that the government was tightening its control over the amount of information it would allow to become public. The CIA and the Defense Intelligence Agency, its military counterpart, started refusing reporters the types of off-the-record briefings that had become almost routine in earlier phases of the crisis.

By computer mail, DIA employees also were ordered not to talk to reporters and to refer all inquiries to the public affairs office. Although this was already DIA policy, one employee could not remember being given such a reminder in the past.

Asked what preparations were going on at the White House, a spokesman said: “The appropriate people will be identified, consulted and informed. I’d rather not discuss the exact procedures. It doesn’t seem a prudent thing to do.”

The five potential terrorist incidents disclosed Tuesday by the FBI officials all involved a “low level” of direction from outside the United States and are significantly below the terrorism that intelligence reports say is directed at U.S. citizens or facilities outside the country, the officials said.

“There are a lot of intelligence reasons to believe there will be efforts by a number of different terrorist organizations to take actions if hostilities break out,” an official said. The assessment is based on public statements by Iraqi President Saddam Hussein and intelligence information, the official said.

Meantime, FBI agents this week are attempting to locate and question about 3,000 Iraqis who have overstayed their visas in the United States, a senior department official said.

“We want to know who they are and why they are staying beyond” the period allowed by their visas, the official said.

The focus on Iraqis in this country with expired visas is the latest “ratcheting up” of government security procedures. It follows Justice Department orders last week that Iraqis and Kuwaitis who enter the United States be identified through registration and fingerprinting.

Only one of the potential terrorist incidents has resulted in public charges--those filed Nov. 29 against Jamal Mohamed Warrayat, a Kuwaiti-born American of Palestinian descent who was arrested in New Jersey on charges of threatening to kill President Bush and Secretary of State James A. Baker III and to damage U.S. facilities.

Some others involved in the more than five possible incidents headed off by the FBI “left the country voluntarily when they became aware of our interest,” one senior official said.