The United States fears al-Qaeda is plotting a big attack inside the country or on US interests but has no plans to raise the terror threat level. It also has no details on when, where or how it might occur, top officials said on today.
"Credible intelligence, from multiple sources, indicates that al-Qaeda plans to attempt an attack on the United States in the next few months," US Attorney General John Ashcroft said at a news conference.
"This disturbing intelligence indicates al-Qaeda's specific intention to hit the United States hard."
Mr Ashcroft said al-Qaeda has declared that preparations for an attack on the United States were nearly complete.
In a news conference with FBI Director Robert Mueller, Mr Ashcroft said al-Qaeda may hope for a similar response to that which occurred after the March 11th train bombings in Madrid.
Those attacks influenced Spain's election and led to the withdrawal of Spanish troops from Iraq.
"Al-Qaeda may perceive that a large-scale attack in the United States this summer or fall would lead to similar consequences," ahead of the US presidential election, Mr Ashcroft said.
"Several upcoming events over the next few months may present especially attractive targets for such an al-Qaeda attack," said Mr Ashcroft.
Those events include the opening of a World War II memorial this weekend in Washington, the Group of Eight summit in Sea Island, Georgia in June, the Fourth of July holiday and the Democratic and Republican Party conventions in Boston and New York at the end of the summer, ahead of the November elections.
Mr Mueller said: "Over the next few months we have reason to believe that there will be a heightened threat to US interests around the world," he said in prepared remarks. "Unfortunately, we currently do not know what form that threat may take.
In a series of television interviews, Homeland Security Secretary Tom Ridge said there were no plans to raise the color-coded terror alert level, which is currently set at "yellow" - the mid-point of the five-point scale - for an "elevated" risk of attack.
At the White House, spokesman Mr Scott McClellan denied the government was overplaying the threat.
"We've continued to receive a stream of credible intelligence reporting over the last couple of months that points to the possibility of an attack or attacks inside the United States," Mr McClellan said. "We know that they would like to have a dramatic effect."