Authorities have identified at least one of the suspects in a terrorist attack planned to coincide with the 10th anniversary of 9/11.
Officials may have the name of one of the suspected bomb plotters after a 24-hour intelligence manhunt, U.S. officials tell ABC News.
The hunt included an analysis of flight logs and other documents following a report from a CIA informant that three people were dispatched by al Qaeda to carry out a bomb plot in the United States, in either New York or Washington.
The intelligence from the informant, who is considered reliable by the CIA, led to the national state of high alert over the possible terror strike on the anniversary of 9/11, but the informant's information itself may be secondhand, ABC News has learned.
Despite the secondhand nature of the source, the high quality of the information led authorities to deem the threat credible, if uncorroborated, and triggered the massive rapid police response in Washington and New York, and the all hands intelligence community and law enforcement manhunt.
New York is closing up tighter than a drum with checkpoints for trucks backing up traffic for miles, and heavy police and National Guard presence at other targets like subways and bus stations.
The hope of authorities in announcing the threat and making a great show of force is to deter the terrorists from carrying out whatever attack they had planned. It's really the best protection we have at this point, given that we have no specific knowledge of a target or timetable.
Will it work? It may cause the terrorists to switch to a Plan B - hit somewhere other than New York or Washington, D.C. While most other police departments are on a higher state of state of alert, it might be easier to penetrate some other target's security than the original.
Let's hope they're closing in on these terrorists and will arrest them before they are able to carry out their plot.