Inside sources have revealed more of what the FBI found at former President Donald Trump’s resort in Mar-a-Lago, including highly classified material surrounding a foreign country’s nuclear capabilities and military defenses. The documents, in Trump’s possession for more than 18 months after he left the White House, were so top secret that “many senior national security officials are kept in the dark about them,” according to The Washington Post, who first reported on the nuclear documents Tuesday night. The publication cited “people familiar with the search,” who spoke on the condition of anonymity. “Only the president, some members of his Cabinet or a near-Cabinet-level official could authorize other government officials to know details of these special-access programs,” the source said, revealing that special clearances are required to obtain such documents, and “not just top-secret clearance.” Which foreign government’s nuclear secrets may have been exposed is unclear, and the source did not provide details surrounding where in Mar-a-Lago it was found, but U.S. intelligence officials are now scrambling with the Office of the Director of National Intelligence “conducting a risk assessment” to determine the damage done by the removal of such classified material. After a previous report by The Post suggesting the FBI was searching for nuclear weapons-related material, Trump replied on social media: “Nuclear weapons issue is a Hoax, just like Russia.”