President Donald Trump said Monday he knows "nothing" about his top national security officials inadvertently texting war plans to a group that included the editor-in-chief for The Atlantic. The officials, including his defense secretary Pete Hegseth, texted war plans for upcoming military strikes in Yemen to a group chat in a secure messaging app that included the editor-in-chief for The Atlantic, the magazine reported in a story posted online Monday. The National Security Council said the text chain “appears to be authentic.” The material in the text chain “contained operational details of forthcoming strikes on Iran-backed Houthi-rebels in Yemen, including information about targets, weapons the U.S. would be deploying, and attack sequencing,” editor-in-chief Jeffrey Goldberg reported. It was not immediately clear if the specifics of the military operation were classified, but they often are and at the least are kept secure to protect service members and operational security. The U.S. has conducted airstrikes against the Houthis since the militant group began targeting commercial and military vessels in the Red Sea in November 2023. Just two hours after Goldberg received the details of the attack on March 15, the U.S. began launching a series of airstrikes against Houthi targets in Yemen. The National Security Council said in a statement that it was looking into how a journalist’s number was added to the chain in the Signal group chat. Government officials have used Signal for organizational correspondence, but it is not classified and can be hacked. The information leak comes as Defense Secretary Pete Hegseth's office has just announced a crackdown on leaks of sensitive information, including the potential use of polygraphs on defense personnel to determine how reporters have received information. Sean Parnell, a spokesman for Hegseth, did not immediately respond to requests for comment on why the defense secretary posted war operational plans on an unclassified app.