Update at 7:40 p.m. ET: The Associated Press cites an unnamed counterterrorism official and a Homeland Security spokesman in confirming the Fox report.

The official said intelligence was received late Wednesday. AP writes, "The information in the threat is so specific and comes so close before the 10th anniversary of the 9/11 attacks that it could not be ignored."

Homeland Security Department spokesman Matt Chandler described the threat as specific and credible but unconfirmed.

Security has been heightened around the country before this weekend's commemoration.

Original post: Citing several U.S. sources, Fox News reports that authorities are investigating what may be a credible terror threat to New York City or the nation's capital days before the 10th anniversary of the Sept. 11 attacks.

According to the report: