Purported ISIS Group Posts Personal Details of 100 U.S. Military Service Members

Group urges violence against those on list.

U.S. officials say the military services are notifying the families of the individuals named on the list.

It said it did so to enable lone wolf sympathizers to kill those named on the list.

U.S. officials said they were aware of the list and were looking into it.

"I can't confirm the validity of the information, but we are looking into it," a Defense Department spokesperson said. "The safety of our service members is always a concern."

Defense officials said the military services were contacting the families of the individuals included on the list.

"The Air Force is cooperating fully with DOD on this matter," Air Force spokeswoman Lt. Col. Holly Slaughter said. "The Air Force is taking the appropriate steps to make sure that everyone who needs to know is notified. As always, force protection is a primary concern."

"Naval Criminal Investigative Service is looking into the matter for the Navy and is taking the appropriate steps to ensure that everyone is notified," said a defense official.

"It is recommended Marines and family members check their online/social footprint, ensuring privacy settings are adjusted to limit the amount of available personal information," Caldwell said. "Vigilance and force protection considerations remain a priority for commanders and their personnel worldwide."

The hacking group claimed it compiled the list from military records, but it appears the photos and information may have come from information available on social media sites or public records. Some of the names appeared in official Defense Department articles about the war on ISIS or other unrelated operations.

Over the past year the military services and regional commands have taken steps requesting its personnel be prudent and limit the amount of personal information posted on social media sites.

ABC News' Mike Levine contributed to this report.