The State Department says a US government employee in southern China reported abnormal sensations of sound and pressure, recalling similar experiences among American diplomats in Cuba who later fell ill.
The department says in an emailed notice to American citizens in China it didn't know what caused the symptoms in the city of Guangzhou, where an American consulate is located.
It says it also didn't know of any other similar incidents in China, but was taking the reports seriously and has informed its official staff in China about it.
In Cuba, the US reported that some of its personnel and family members experienced a range of ailments, some after hearing an unusual sound. For most, the symptoms occurred around May 2017. The still-unexplained incidents sparked a rift in US-Cuban relations.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)