Last Updated Apr 15, 2015 1:25 PM EDT
Federal law enforcement officials are investigating the online publication of home addresses of senior officials and former officials of the Department of Homeland Security, the Federal Bureau of Investigation and other agencies, CBS News has learned.
Investigators became aware of the incident Tuesday, reports CBS News correspondent Jeff Pegues.
In this case, however, sources tell CBS News that investigators believe an apparent right-wing extremist group is behind the posting of the information.
In a statement, DHS said: "The safety of our workforce is always a primary concern. DHS has notified employees who were identified in the posting and encouraged them to be vigilant. DHS will adjust security measures, as appropriate, to protect our employees."
An FBI official told CBS News investigative producer Pat Milton that the agency was aware of the posting and was attempting to locate the source.
A message along with the posting titled "DHS-CIA-FBI TRAITORS HOME ADDRESSES" states:
"LET THESE EVIL NWO SATANISTS KNOW THAT THERE WILL BE HELL TO PAY FOR THEIR 911 TREASON, AND THEIR FUTURE FEMA CAMP PLANNED PUBLIC CRACKDOWN TREASON ALSO
JESUS IS LORD, AND THE PUBLIC IS IN CHARGE, NOT THESE SATANIC NWO STOOGES"
Investigators are trying to track down the source or sources of the disclosure.
The Pentagon was forced last month to notify about 100 service members who appeared on an ISIS "hit list," and bases where they are stationed contacted local law enforcement agencies in an effort to increase police patrols in the neighborhoods where they live, reported CBS News national security correspondent David Martin.
ISIS had urged its followers and sympathizers in the U.S. to kill American service members on the list. They were identified with names, photos and addresses.
Pentagon officials said the list appeared to be drawn from public sources -- everything from newspaper interviews to Facebook pages that connected them, sometimes incorrectly, with the war against ISIS.
So far there have been no reports of any members of that list being attacked.