The FBI has opened a federal investigation over the leak of top secret U.S. intelligence documents regarding Israel's preparation for an attack against Iran. Why it matters: The leak was one of the most serious security breaches within the U.S. intelligence community in years.

The FBI is investigating the public disclosure of a pair of highly classified intelligence documents describing Israel's preparations for a retaliatory strike on Iran, the bureau said on Tuesday.

American officials are trying to determine the source of the leak, which describes military drills and weapons placement, and how damaging it might be.

Fox News senior strategic analyst Gen. Jack Keane (Ret.) on the latest from the war in Israel as fighting continues against Hezbollah as the U.S. probes an intel leak of Israel attack preparations.

The U.S. is investigating an unauthorized release of classified documents that assess Israel's potential plans to attack Iran.

The FBI is investigating the leak of a pair of highly classified intelligence documents describing Israel's preparations for a retaliatory strike on Iran, the Washington Post reported on Tuesday. "The FBI is investigating the alleged leak of classified documents and working closely with our partners in the Department of Defense and Intelligence Community,

Israel plans to strike Iran in retaliation for a ballistic missile attack this month. Iranians fear the response will destabilize the economy and stir unrest.

Documents, published online to messaging app Telegram, were marked "top secret," but it is not yet clear if they are authentic.

The documents posted on social media have markings that would indicate that they originated from the National Geospatial Intelligence Agency (NGA).