A puzzling array of symptoms dubbed the “Havana Syndrome” after it impacted a number of US officials at the American consulate in Havana befell two Trump Administration national security officials in 2020 in Washington, DC, CNN reports.

Both officials, who worked with the National Security Council, experienced nervous system irregularities, including headaches, sleepiness and other effects.  One was reportedly struck with a mild case as he traveled across the Capitol Ellipse the day after the 2020 election; the second felt more severe effects a couple weeks later and sought medical attention from the White House medical team.

The condition was identified after more than a dozen employees of the US consulate in Havana reported suddenly experiencing headaches, dizziness, vertigo, nausea and other symptoms while working at the compound.  According to recent reporting by the New York Times, another person suffered a similar incident in the past two weeks, and more than 130 have been reported, both domestically and around the world.

No specific thing has been identified as the cause of the symptoms, although speculation ranges from a directed energy beam, such as microwave energy, or subsonic noise.  Some people have reported they recovered from the symptoms after moving to a different room; others say the condition lingers.

“The whole ‘microwave’ theory is not because someone has any intelligence to suggest it, or someone saw it happen,” said one source familiar with the intelligence on the matter. “This is what’s been so maddening. It’s based purely on symptoms. We have no hard leads — just all circumstantial evidence. And it’s circumstantial evidence that could also be something completely different.”