An ABC News report quoted intelligence officials as saying that at least three individuals (reportedly from Afghanistan), including an American citizen "entered the country in Aug 2011 by air with the intent to launch a vehicle-borne attack against Washington DC or New York around the anniversary of 9/11."
Earlier several reports claimed that al-Qaeda led by the then leader Osama bin Laden had planned to strike another 9/11 like attack on the country.
Citing the intelligence report, President Barack Obama's men reportedly started scanning every inch of the nation and security all around the country has been beefed up.
White House officials also have been quoted as saying, "The President was briefed on this specific threat information this morning and has been updated on it throughout the day. The US government has already significantly enhanced its security posture in advance of the 9/11 anniversary to protect the country against possible terrorist threats."
Continuing their statements, the officials also added, "Nevertheless, the President directed the counter terrorism community to redouble its efforts in response to this credible but unconfirmed information."