(Newser) – The Canadian government said Thursday that at least one Canadian diplomat in Cuba has been treated for hearing loss, following disclosures that a group of American diplomats in Havana suffered the same. US officials believe they were caused by an advanced sonic device, per the AP. Global Affairs Canada spokeswoman Brianne Maxwell said Canadian officials "are aware of unusual symptoms affecting Canadian and US diplomatic personnel and their families in Havana" and were working to figure out the cause. In the fall of 2016, US diplomats began suffering unexplained losses of hearing, according to officials with knowledge of the investigation. Several were recent arrivals at the embassy, which reopened in 2015 as part of President Obama's reestablishment of diplomatic relations with Cuba.

Some of the US diplomats' symptoms were so severe that they were forced to cancel their tours early and return to the United States, officials said. After months of investigation, US officials concluded that the diplomats had been attacked with an advanced sonic weapon that operated outside the range of audible sound and had been deployed either inside or outside their residences. It was not immediately clear if the device was a weapon used in a deliberate attack, or had some other purpose. State Department spokeswoman Heather Nauert said the US retaliated by expelling two Cuban diplomats from their embassy in Washington on May 23. The Cuban government said that "Cuba has never permitted, nor will permit, that Cuban territory be used for any action against accredited diplomatic officials or their families, with no exception." (Read more Cuba stories.)

