Terror Threats Mar 9/11 Anniversary
PHOTO: A bomb squad member investigates a suspects car at Los Angeles Airport on September 11, 2013 after a threat was made at the airport.

Federal authorities warned overnight of an attack threat targeting Los Angeles International Airport and New York's John F. Kennedy International Airport, but questioned the seriousness of the threat.

In the hours leading up to the twelfth anniversary of the 9/11 attacks, federal authorities repeatedly said they had found no specific, credible threats to the U.S. homeland. But that doesn't mean they haven't been busy chasing down specific threats with – at best – questionable credibility.

Overnight, the FBI and Department of Homeland Security notified law enforcement agencies across the country of the threat information, ABC News has learned.

According to a notice from the FBI and DHS, a man told authorities he had information indicating the head of al-Qaeda, Ayman al-Zawahri, was in the "final stages" of coordinating a spectacular attack in Los Angeles and New York City.

The man said the attack would target Los Angeles International Airport and John F. Kennedy International Airport, according to the notice. What's more, he claimed three Columbia University students have already been recruited to wear explosives-laden suicide vests and detonate them at the New York airport, according to the notice.

The bombing in New York would be followed by a second attack involving men posing as New York City taxicab drivers, the alert said the man told authorities.

Authorities said they were "highly suspect" about the source of the information and noted in the alert to local police departments that the source said he would provide even more information if the U.S. government gave him a "large and specific" amount of money. They also said his information has yet to be corroborated. However, because his information was so specific, the FBI and DHS passed it along out of an abundance of caution, sources said.

Authorities are currently assessing the man who provided the tip, and his life and associations are being dissected.

The New York Police Department does not believe the threat is credible and is positioning no additional resources, a law enforcement source said.

"The FBI and our Joint Terrorism Task Force receive hundreds of threats daily, and we work around the clock with our partners to protect this city and nation," the FBI said in a statement. "We remain on a heightened state of alert, but stress that there is no specific or credible threat at this time."

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