CBS News obtained medical records from U.S. diplomats in Cuba that show doctors diagnosed them with brain injuries from possible sonic attacks while in Havana. From CBS News:

The diplomats complained about symptoms ranging from hearing loss and nausea to headaches and balance disorders after the State Department said “incidents” began affecting them beginning in late 2016. A source familiar with these incidents says officials are investigating whether the diplomats were targets of a type of sonic attack directed at their homes, which were provided by the Cuban government. The source says reports of more attacks affecting U.S. embassy workers on the island continue.

The doctor, one of several who reviewed their cases, included a warning in the medical records about the health risks of future exposures. The diplomats underwent comprehensive audiological evaluations and a battery of other tests.

Diplomats have suffered harassment other types of harassment on the island, “including vehicle vandalization, constant surveillance, and home break-ins.”

These sonic attacks have forced many diplomats to cut short their stay in Cuba.

The news of these attacks surfaced earlier this month when State Department officials spoke to CNN:

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. “We have worked with the Cubans to try and find out what is going on. They insist they don’t know, but it has been very worrying and troublesome.”

“It’s very strange,” one official said.

The officials do not know the extent of the involvement of the Cuban government, but one officials said someone within the regime must have been involved “because Cuba’s security services exercise such a tight grip over the country.” Cuban officials denied involvement. From Fox News:

Cuba’s Ministry of Foreign Affairs released a statement August 9 denying allegations.

“Cuba has never, nor would it ever, allow that the Cuban territory be used for any action against accredited diplomatic agents or their families, without exception,” the ministry said. “Moreover, it reiterates its willingness to cooperate in the clarification of this situation.”

Our government has taken action against Cuba:

Some of those affected chose to return to the US, said Nauert, prompting the administration to expel two Cuban diplomats from the embassy in Washington in May.

“The Cuban government has a responsibility and an obligation under the Geneva convention to protect our diplomats,” Nauert told reporters, “so that is part of the reason why this is such a major concern of ours.”

“We felt like we needed to respond to the Cubans and remind them of their responsibility under the Vienna convention,” one of the officials said. The officials were not declared “persona non-grata” and may be allowed to return back to the United States if the matter is resolved.