WASHINGTON — At least 16 Americans associated with the US Embassy in Cuba suffered hearing loss and other problems while in Havana, the State Department said.

It was the first accounting of the scope of what the government suspects was deliberate targeting of US diplomats. Secretary of State Rex Tillerson has confirmed that Americans serving in Havana began having symptoms that were at first unexplained but were later found to be related. They started reporting problems late last year, at the end of the Obama administration. But the cause remains a mystery.

The State Department suspects some sort of ‘‘acoustic attack.’’ The Cuban government, which has denied any involvement, is cooperating with the US investigation, officials said.

CBS News reported that doctors diagnosed brain injuries that led to complaints of nausea, hearing loss, headaches, and balance loss.

Washington Post