WASHINGTON (CNN) — A plot to carry out a large-scale terror attack against the United States in the near future is being directed by Osama bin Laden and other top al Qaeda members, senior intelligence officials said Thursday.
Bin Laden and his top lieutenant, Ayman al-Zawahiri, are overseeing the attack plans from their remote hideouts somewhere along the Afghanistan-Pakistan border, according to senior intelligence officials.
“This type of plotting, this type of operational activity, is being done with the direct direction and authorization of that senior leadership,” said one official, who spoke on condition of anonymity.
A Democratic senator who attended Thursday’s CIA and FBI briefing said, “It is the most worrisome situation since 9/11” without elaborating specifically.
Arrests of terror suspects in Europe and the Middle East resulted in the new warning, said Homeland Security Secretary Tom Ridge.
“We lack precise knowledge about time, place and method of attack,” he said. “But along with the CIA, FBI and other agencies, we are actively working to gain that knowledge.”
A senior U.S. intelligence official said the warning was based on “a very strong body of intelligence.”
The planned attack is “an effort to disrupt the democratic process” before November’s elections, Ridge said.
Ridge said he had no specific or credible information about threats to the upcoming political conventions. The four-day Democratic convention kicks off July 26 in Boston, Massachusetts, and the Republican National Convention begins August 30 in New York City.
He also said the nation’s color-coded terrorist threat level will remain at yellow, or elevated, he said.
“We have more protective measures in place at yellow today than we did six months or a year ago,” Ridge said. “And there will be more put in place on a day-to-day basis every single day, for as long as the department exists.”
“We know they have the capability to succeed and they also hold the mistaken belief that their attacks will have an impact on America’s resolve,” Ridge said.
Possible Madrid model of attack
Sources said al Qaeda is plotting an attack similar to the Madrid train bombings, which killed nearly 200 people just days before Spain’s elections in March.
Spain’s elections resulted in the ouster of a conservative government that had joined the United States in the 2003 invasion of Iraq.
The opposition Socialists had campaigned on a pledge to withdraw Spanish troops from Iraq.
“They are focusing on what they perceive to have been successful attacks in Madrid as far as the impact on the electoral process there and the outcome of that election,” the official said. “The reporting that we are seeing, the information that we have, is tied to the different types of democratic processes here.”
Another senior intelligence official said authorities are concerned about polling places being targeted during the elections, and they are trying to come up with a protection plan.
A third intelligence official said there is particular concern about possible attacks using backpack explosives — as were used in Madrid — or car or truck bombs to destroy bridges, tunnels or other targets.
In April, arrests were made in Canada and Pakistan in connection with an alleged plot to set off a large bomb in London, the official said. The first official said al Qaeda also remains interested in targeting locations it has struck in the past.
“There are strong indications that al Qaeda will continue to try to revisit past targets, those that they were able to attack as well as those they were unable to attack,” he said. “In addition, there is intelligence that indicates that they are looking at various transportation systems.”
Al Qaeda remains “very interested” in using aviation, he added.
“We know that it is a consistent focus of their efforts as we saw in 9/11 and despite the numerous security enhancements that have been made, al Qaeda continues to pursue capabilities that can use aircraft either as weapon or as targets,” the official said.
Anti-terrorism efforts have degraded al Qaeda’s abilities, but the organization remains strong because of its flexibility and adaptability, one official said.