Since 2016, nearly 50 U.S. diplomats in Cuba and other countries have been hit with so-called Havana Syndrome—a mystery illness with symptoms like ringing in the ears, loss of hearing and balance, and headaches. But, according to a Politico report, U.S. troops in the Middle East have been targeted, too. Citing unnamed sources, the report says Pentagon officials believe Russia is most likely the mastermind of multiple directed-energy attacks on troops since last year. In one of several incidents, military personnel in Syria developed flu-like symptoms. Investigators passed their findings onto lawmakers but cautioned that attribution can be hard because there is no physical evidence of a weapon.

“We still have no idea what the hell is going on at the embassy in Cuba,” said Jeffrey Lewis, a national security expert at the Middlebury Institute. “Those people have been reporting all those symptoms for years and the question is, are they being targeted? Is this some eavesdropping equipment that’s having an effect on them? You just don’t know.”