At least four US diplomats stationed in Europe appeared to be victims of the mysterious "Havana Syndrome," Report informs referring to The Wall Street Journal.
Three were located at diplomatic missions in Geneva, Switzerland, and one was located in Paris, France, The Journal said. At least one person from the Geneva trio was evacuated to the US to receive medical treatment, it added, according to Business Insider.
The Journal did not name the four officials. The State Department did not immediately respond to a request for comment from Insider.
The so-called Havana Syndrome is a mysterious neurological ailment that has perplexed scientists and the US government, which has labeled it an "anomalous health incident." It was named after the site of the first reported attack, in Havana, Cuba, in 2016.
Symptoms include headaches, vertigo, hearing loss, and the appearance of buzzing or clicking sounds.
More than 200 US diplomats, intelligence operatives, and other personnel stationed outside the US have reported symptoms since 2016.
US officials reportedly believe the ailment may be caused by a directed-energy attack and suspect that a foreign power could be responsible for the attacks.