NYC responds to 'credible' terror threat

New York's law enforcement agencies ratcheted up security around the city Thursday as counterterrorism officials revealed an unconfirmed but "credible threat" of a car or truck bomb attack aimed at Sept. 11 commemoration events in New York and Washington.

As officials took pains to urge people not to panic despite the threat, New York Police Commissioner Ray Kelly said, "We are taking additional precautions."

He said police will be holding tours of certain units over for four hours at a time, from now until at least Monday, to enhance the officers working in patrol, transit and counterterrorism units and traffic units. The city is also increasing its critical response vehicles, which respond to selected areas for counterterrorism coverage.

Kelly said the public should be prepared to be inconvenienced by vehicle checkpoints and that bag inspections will be increased in the subway system. More bomb dogs will be on patrol, as will more police vehicles with license plate readers and radiation monitoring units.

"Federal authorities announced that they had received credible information that terrorists may be plotting an attack in the coming days," Mayor Michael Bloomberg said at a news conference in Manhattan.

"The threat at that moment has not been corroborated," he stressed, adding, "But we do live in a world were we must take these threats seriously."

The threat emerged about two days ago and prompted counterterrorism officials to brief and regularly update President Barack Obama on it beginning Thursday morning as agencies stepped up their vigilance, a White House official said.

"The president directed the counterterrorism community to redouble its efforts in response to this credible but unconfirmed information," the official said.

The Associated Press reported Thursday that the threat law enforcement officials were investigating concerned three people who recently entered the United States. "There is specific, credible but unconfirmed threat information," said Department of Homeland Security spokesman Matthew Chandler, who said all agencies "will continue to take all steps necessary to mitigate any threats that arise."

The threat was deemed serious by Homeland Security Department officials, as counterterrorism officials Thursday also began briefing key members of Congress, including Rep. Peter King (R-Seaford), chairman of the House Homeland Security Committee. "It is a very specific threat. It's a credible threat. But it hasn't been confirmed," King said in an interview. "It's being taken very seriously by all the agencies."

A terrorism expert, who didn't want to be identified said the intelligence "asset" that was the source of the information had been reliable in the past but that the information had to be corroborated. The source said police agencies were being alerted Thursday night to the potential for a car-bomb attack.

King said he received a briefing from Obama's chief counterterrorism adviser, John O. Brennan, Thursday morning in which he talked about the latest threat information. King described Brennan's demeanor as one of "serious concern, but not tension," with the feeling that the information was something that had to be checked out.

Washington officials have said they will increase police presence, mirroring heightened security across the country.

Homeland Security officials tied the threat to 10th anniversary events in New York and Washington of the Sept. 11 attacks on the World Trade Center and Pentagon.

"As we know from the intelligence gathered from the Osama bin Laden raid, [al-Qaida] has shown an interest in important dates and anniversaries, such as 9/11," Chandler said. "In this instance, it's accurate that there is specific, credible but unconfirmed threat information." He warned intelligence and counterterrorism officials may get more reporting as Sunday nears.

"Sometimes this reporting is credible and warrants intense focus, other times it lacks credibility and is highly unlikely to be reflective of real plots under way," he said.