Story highlights The employees affected were not at the same place at the same timeThey suffered a variety of physical symptoms since late 2016 resembling concussionThe FBI is now looking into the matter. One official said the employees could have suffered permanent hearing loss as a result. The employees affected were not at the same place at the same time, but suffered a variety of physical symptoms since late 2016 which resembled concussions. The State Department raised the incidents with the Cuban government over the course of several months and sent medical personnel to Havana, but have not been able to determine exactly what happened. "It can be quite serious," one official told CNN.

Source: CNN August 09, 2017 21:50 UTC