US investigates after 16 Americans suffer hearing loss in Cuba
At least 16 Americans working for the US government in Cuba suffered symptoms as a result of activity attributed to a covert sonic device, the United States has said.
The diplomats suffered severe hearing loss.
This is the first time the US has disclosed a number of Americans affected.
State department spokeswoman Heather Nauert said it is possible there are more.
All of the 16 are US citizens, she said, and they have been treated by doctors either in Cuba or the US.
Ms Nauert said the incidents are no longer occurring, b ut she said the US has not located a device that caused the symptoms and has not identified the perpetrator.
Some of the 16 are still in Cuba and others have returned to the US.
Ms Nauert said Cuba is co-operating with the US investigation.