Sixteen U.S. officials were harmed in Cuba in a mysterious incident targeting U.S. diplomats sent to Havana, the State Department confirmed Thursday.

"We can confirm that at least 16 U.S. government employees, members of our embassy community, have experienced some kind of symptoms," State Department spokeswoman Heather Nauert told reporters at a press briefing. "They have been provided medical treatment in the United States, as well as in Cuba."

Nauert could not immediately confirm whether that figure included family members of the personnel. She said some of those harmed are still in Cuba, although some returned to the United States.

The State Department has said the incident is still being investigated, but various reports have said U.S. officials may have been hurt by an "acoustic attack" that covered many people working at the embassy.

Initial reports were that about five officials were harmed.

White House spokeswoman Sarah Sanders declined to add more details and said there is an ongoing review of what happened in Cuba, although she did say President Trump has been briefed on it. She referred all other questions to the State Department.