(CNN) -- U.S. officials from the president down tried Tuesday to downplay the leak of tens of thousands of documents about the war in Afghanistan, a disclosure experts are calling the biggest leak since the Pentagon Papers about Vietnam.
Pentagon officials have not found anything top-secret among the documents, a Defense Department spokesman said.
"From what we have seen so far, the documents are at the 'secret' level," Col. David Lapan said. That's not a very high level of classification.
Lapan emphasized that the Pentagon has not looked at all of the more than 75,000 documents published on WikiLeaks.org on Sunday.
President Barack Obama said Tuesday that he is "concerned about the disclosure of sensitive information" about the U.S. mission in Afghanistan but asserted that the documents don't shed much new light on the issue.
CNN
