Leaders briefed on 'specific threat' for 9/11 anniversary

President Obama and a top-ranking member of Congress were briefed Thursday on a “specific and credible” threat to the U.S. in advance of the 10th anniversary of the September 11, 2001 terrorist attacks. 

"The President was briefed on this specific threat information this morning and has been updated on it throughout the day," a White House official said.

“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.”

Sen. Susan CollinsSusan Margaret CollinsBipartisan group of lawmakers aim to reform US sugar program A bipartisan bridge opens between the House and Senate Gaming the odds of any GOP tax bill getting signed into law MORE (R-Maine), the ranking Republican on the Senate Homeland Security and Government Affairs Committee, was briefed in a classified setting at least twice on Thursday about a threat by terrorists to attack Washington D.C. and New York City.

The Department of Homeland Security (DHS) said in a statement that the threat was “specific and credible, but unconfirmed." 

“As the Ranking Member of the Senate Homeland Security Committee, this morning I received a classified briefing on the terrorist threat from the Department of Homeland Security's Under Secretary for Intelligence and Analysis Caryn Wagner,” said Collins in a statement late Thursday night.

“She briefed me on the nature of the threat, which is both specific and credible.”

Collins said she was briefed again by John Brennan, President Obama’s chief counterterrorism advisor, Thursday evening.

“I am confident that the Administration is taking the threat seriously and sharing intelligence with state and local enforcement officials in the targeted locations,” said Collins.

A counterterrorism official told the AP that the threat was received Wednesday night.

DHS said information gathered in the raid that killed Osama bin Laden showed al Qaeda's interest in striking on important dates but maintained the current threat was unconfirmed.

"In this instance, it’s accurate that there is specific, credible but unconfirmed threat information," DHS spokesman Matthew Chandler said in a statement. "As we always do before important dates like the anniversary of 9/11, we will undoubtedly get more reporting in the coming days."

New York City Mayor Michael Bloomberg would not elaborate on the threat's details, but said local officials were reacting.

"We've taken the appropriate steps and we thought it's in the public's interest to know and also we want the public to be vigilant," Bloomberg said.

House Intelligence Committee member Rep. Michele BachmannMichele Marie BachmannBachmann praises Trump as man of faith Tom Petty dies at 66 Bachmann: Muslim immigrants trying to undermine Western civilization MORE (R-Minn.) said the terror threat is getting "full attention of the United States" government.

"This is an issue that is being paid close attention to by not only the members of the intelligence committee but by the administration and members of Congress and those at the Justice Department," Bachmann said at a press conference on Thursday night.

Calling it a "potential threat to New York and people around the United States," the Minnesota lawmaker said that "it would be inappropriate to give any details on this at all," including briefings that members of the intelligence committee may have had on the matter.

Collins warned Americans to be extra vigilant in identifying possibly suspicious activity. DHS launched its “See something, say something” campaign earlier this year, which depends largely on the public and private businesses to inform law enforcement officials of suspicious behavior they observe.

“The public should be alert to any suspicious activity and report such concerns to local law enforcement. If you 'see something, say something,' as the Department of Homeland Security advises.”

—Sam Youngman, Daniel Strauss and Molly K. Hooper contributed.

This post was updated at 11:50 p.m.