At least 24 Americans and eight Canadians reported a mysterious range of symptoms while stationed at embassies in Cuba.

The RCMP is leading the investigation into what is causing a mysterious range of symptoms among Canadian diplomats and their families in Cuba over the past year, and three diplomatic families who had been posted to Cuba over the summer have since opted to return out of concerns over what officials are characterizing as uncharted territory.

Whether there's a direct relationship between the sound and the physical damage suffered by the victims is unclear.

The U.S. is warning Americans against visiting Cuba and ordering more than half of U.S. personnel to leave the island in response to what they described as "specific attacks" on diplomats.