U.S. State Department spokesperson Heather Nauert would not confirm the number of U.S. diplomats affected or the severity of their symptoms, saying only that they had "a variety of physical symptoms" that had caused some to return to the United States.
In a statement issued Wednesday evening, the Cuban government said it had never allowed the island to be used for actions against diplomats and was willing to cooperate to clarify "incidents".
Nauert did not say how many USA diplomats were affected nor confirmed they had suffered hearing loss.
A months-long USA investigation found that a group of American diplomats were attacked with an advanced sonic weapon that operated outside the range of audible sound and had been emitted either inside or outside their homes, according to the AP report. "We don't have any definitive answers about the source or the cause of what we consider to be incidents", Nauert said. At the moment, the United States can not blame any individual or country in the incident, she added.
The Miami daily El Nuevo Herald reported that USA diplomats would have lost hearing capacity while working in Cuba, prompting a federal investigation and the expulsion of two Cuban diplomats from the United States. "At this time, we do not have any reason to believe Canadian tourists and other visitors could be affected". "When I say an active investigation is underway, in part what that means is, we don't know exactly where this came from".
Deepening the scale of the incident, the Canadian government said some of its personnel had experienced similar symptoms.
Global Affairs Canada spokeswoman Brianne Maxwell said Thursday that agency officials "are aware of unusual symptoms affecting Canadian and US diplomatic personnel and their families in Havana".
Sen. Marco Rubio, R-Fla., a staunch critic of former President Obama's decision to reopen relations with Cuba after decades of Cold War isolation, said: "U.S. personnel working in Havana for decades".
According to a statement released Wednesday by the Cuban government, the foreign ministry was made aware of the incidents on February 17 and promptly launched an investigation into the matter.
Two staffers at the Cuban embassy in Washington were expelled in May, suggesting retaliation for a dark incident whose precise nature and details are still being investigated. The Obama administration also approved a package of regulatory changes that was meant to expand scientific, humanitarian, trade and commercial opportunities between the US and Cuba.
The FBI is reportedly looking into the issue, with the Cuban government high atop the list of suspects. Meanwhile, Cuba had strengthened security around the United States embassy, diplomatic and staff residences.
The US believes several State Department employees at the US embassy in Havana were subjected to an "acoustic attack" using sonic devices that left at least two with such serious health problems they needed to be brought back to the US for treatment, several senior State Department officials told CNN.
About five diplomats, several with spouses, were affected, the AP said. That's also true for Cuba, but as the Post's Anne Gearan notes, the Castro regime has a long track record of harassing diplomats for countries foolish enough to establish diplomatic relations with them.