A U.S. government employee working in China was reportedly diagnosed with a mild traumatic brain injury after reporting "abnormal sensations of sound and pressure."
That may seem familiar — the U.S. recalled several employees from Havana, Cuba, after they said they experienced similar auditory sensations and medical symptoms.
Secretary of State Mike Pompeo linked the two situations when he testified before Congress on Wednesday.
"We had an incident in Guangzhou that the medical indications are very similar and entirely consistent with the medical indications that have taken place to Americans working in Cuba," he said.
It's not clear yet what caused the injury to the employee in China; the State Department says it's not aware of any other similar cases there. But the department did issue a warning to other employees there. The health alert said not to look for the source of any strange sounds, but to move to a place where the sounds aren't present.