BOSTON (CBS/AP) – Just days before the 10th anniversary of the Sept. 11 attacks, U.S. counterterrorism officials were chasing a credible but unconfirmed al Qaeda threat to use a car bomb on bridges or tunnels in New York City or Washington. It was the first “active plot” timed to coincide with the somber commemoration of the terror group’s 9/11 attacks a decade ago that killed nearly 3,000 people.
Counterterrorism officials were investigating the threat throughout the night and into Friday, as police in New York and Washington said they would increase their already stepped-up staffing levels in light of the recent intelligence.
The threat originates from Pakistan and what remains of al Qaeda’s core leadership, including its new head Ayman al Zawahiri, reports CBS News homeland security correspondent Bob Orr.
WBZ NewsRadio 1030′s Carl Stevens reports from Ground Zero in New York
Law enforcement officials have been particularly wary after information gleaned from Osama bin Laden’s compound in Pakistan indicated that al Qaeda had considered attacking the U.S. on this anniversary and other important American dates. A federal law enforcement source also told CBS News that operatives may be acting on bin Laden’s wishes.
WBZ-TV’s Jim Armstrong reports
Law enforcement officials were pursuing three people who may be traveling to the U.S. or who have recently entered the country, based on the detailed information received by the U.S. intelligence community late Wednesday, officials said. The intelligence suggested that al Qaeda planned to car bomb one or both of the two cities that were hit 10 years ago.
WBZ NewsRadio 1030′s Karen Twomey reports on Boston’s stepped-up security
One official tells CBS News the government decided to alert the public because, “there are enough specifics in the threat to make it more than ‘aspirational’.”
But the threats remain unconfirmed and there is a full court press by the FBI, CIA and others to refute or corroborate the information.
The FBI and Homeland Security Department issued a joint intelligence bulletin Thursday night to law enforcement around the country urging them to maintain increased security and be on the lookout for suspicious activity.
In Boston, despite the city not being singled out, the mayor says police are on alert.
Boston police Commissioner Ed Davis said his officers were working with other state agencies.
“We’ll be working closely with the State Police and the Transit Authority and more particularly, paying attention to transit hubs in this and every potential threat related to 9/11,” Davis told WBZ NewsRadio 1030’s Karen Twomey on Friday.
“T” officials say they were planning to ramp up security efforts even before yesterday’s threat.
Security officials at Logan Airport were taking the threats “very seriously.”
Massachusetts Port Authority Interim CEO David Mackey said security officials are “certainly ready to protect the airport this weekend.”
Mackey, airport and airline employees were among those who gathered at Logan’s 9/11 Memorial Friday to remember those killed on the two flights from the airport that were hijacked and flown into the World Trade Center.
Mackey said Logan “will adjust the measures that we are going to take this weekend whether in a visible or not visible way to meet whatever the threat is.”
Briefed on the threat information Thursday morning, President Barack Obama directed the U.S. counterterrorism community to redouble its efforts, a White House official said.
Word of the threat came hours after Homeland Security Secretary Janet Napolitano told reporters that there was “a lot of chatter” around the anniversary of the attacks but that there was no information about a specific threat.
Napolitano had been briefed on early interpretations of the threat that morning as intelligence officials were still trying to determine the validity of the information. It later became clear that the threat was specific and credible and could not be dismissed, even though it has not been confirmed.
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