Releasing operational details of Osama Bin Laden's targeted killing was a breach of security that could endanger the men who carried out the mission, as well as their families, CNN reports.

US Defense Secretary Robert Gates said Thursday the Department of Defense is looking into ways to "pump up the security" for Navy SEAL's who carried out the Osama bin Laden after they expressed concern for their safety, - and the safety of their families.

Gates, attending a town hall meeting in Camp Lejune, North Carolina, made the statement in response to a question by a Marine who asked what measures were being taken to protect "the identities and the lives" of the SEALs involved in the take-down of bin Laden in Pakistan a week ago.

"We are very concerned about the security of our families – of your families and our troops," Gates told those present. "And also these elite units that are engaged in things like that. And without getting into any details ... I would tell you that when I met with the team last Thursday, they expressed a concern about that, and particularly with respect to their families."

"Frankly, a week ago Sunday, in the Situation Room, we all agreed that we would not release any operational details from the effort to take out bin Laden. That all fell apart on Monday, the next day," Gates admitted.

SEALs, short for Sea, Air and Land teams, are known as "quiet professionals." They keep a low profile because of the classified - and dangerous - nature of their operations.

It is widely believed United States Naval Special Warfare Development Group (DEVGRU), informally known by its former name, SEAL Team 6, has returned to American soil. But the unit has traditionally operated under such a degree of secrecy that the military won't confirm its whereabouts.

The Marine's question underscored sentiment in the US military and intelligence communities that identification of SEAL Team 6 as the team responsible for the mission signified an unprecedented breach of confidentiality.

Gates acknowledged the threat of retaliation against Team 6 and troops deployed in the region.

"There is an awareness that the threat of retaliation is increased because of the attacks – because of the action against bin Laden," Gates said.

"The one thing I would tell you, though, is that I think there has been a consistent and effective effort to protect the identities of those who participated in the raid, and I think that has to continue," Gates concluded.

A Pentagon spokesman later told CNN Gates' response should not be taken "as a criticism of any particular person or office."

"He was indeed voicing his concern about the breakdown in operational security after the killing of Bin Laden," Deputy Assistant Secretary of Defense Geoff Morrell said. "Anonymous sources revealing secret information about the tactics, training, and equipment of covert forces put at risk our ability to successfully mount similar missions in the future."