Bloomberg Briefs on 9/11 Threat

NYC Mayor says "threat has not been corroborated" but urges NYers to remain vigilant until confirmed or dismissed. Refused to discuss source of threat.

See further updates here.

NYPD sources tell Daily News threat involves a planned car bomb attack in either New York City and/or D.C.

Fox News reports authorities have general description of up to three possible suspects but no names.

DHS spokesperson calls threat "specific, credible but unconfirmed."

From WH Official: "The President was briefed on this specific threat information this morning and has been updated on it throughout the day. The United States government has already significantly enhanced its security posture in advance of the 9/11 anniversary to protect the country against possible terrorist threats. Nevertheless, the President directed the counterterrorism community to redouble its efforts in response to this credible but unconfirmed information."