Doctors and scientists are inching towards solving the mystery behind unusual sounds and strange sensations that had caused illness among US diplomats and their families in Cuba and China.
They suspect unconventional microwave weapons may be behind these mysterious ailments, The New York Times reports.
The victims had complained of nausea, severe headache, fatigue, dizziness, sleep problems and hearing loss after being bombarded with strange, high-pitched sounds in their hotel rooms or homes.
Doctors, who examined 21 such cases in Cuba, did not confirm microwave weapons as the cause of the ailments in a study published in a medical journal earlier this year.
However, the team head, Douglas Smith, director of the Center for Brain Injury and Repair at the University of Pennsylvania, told theTimes that microwave weapons are now the main suspect. The team also believes the victims had suffered brain injury.
The US authorities did not comment on the possible role of microwave weapons in the cases. But if the doctors prove it, the US state department and FBI will have to find the culprits who used these weapons and their motive.
Since there was no tangible evidence to nail any suspect, the US blamed Cuba for the sonic attacks in September last year and recalled several embassy officials. In a tit-for-tat, it also expelled 15 Cuban diplomats from Washington.
Cuba denied any role in these mysterious cases.
Several months later, some of the US diplomats in China too started complaining about similar sounds followed by ailments.
One officer, who was posted in the southern Chinese city of Guangzhou, showed symptoms of ailments between late last year and April this year. After being sent to the US for medical check-up, the unnamed official was diagnosed with mild traumatic brain injury in May.
Americans diplomats working in China were then told to consult a doctor if they face similar symptoms. An embassy note said if officials hear strange and piercing sounds in their hotel rooms or homes in China, they should move away from the source of the sound instead of trying to locate it.
Decades ago, it has been scientifically proven that human brain can perceive microwaves as sound. If individuals are bombarded with microwaves, it could affect their normal behaviour, cause them pain and even immobilise them.