"Exercise increased caution in Cuba due to attacks targeting US Embassy Havana employees resulting in the drawdown of embassy staff," the advisory said.
The State Department specifically urged Americans to avoid Hotel Nacional and Hotel, advised them where to seek medical care in Cuba if affected by any acute auditory or sensory phenomena and suggested to immediately move to another area.
US Embassy employees in Havana "appear to have been targeted in specific attacks" and suffered injuries, the State Department noted.
"Affected individuals have exhibited a range of physical symptoms including ear complaints and hearing loss, dizziness, headaches, fatigue, cognitive issues, visual problems and difficulty sleeping," the advisory said.
The State Department pointed out that the US Embassy in Cuba is currently working with reduced staff and family members cannot accompany US diplomats there.
More recently, US diplomats in China also complained of symptoms similar to the ones suffered by their colleagues in Cuba.
READ MORE: US Diplomat in Havana Confirmed to Have Sonic Attack Symptoms — State Department
In June, US Secretary of State Mike Pompeo announced that the State Department had established a task force to respond to the mysterious acoustic incidents overseas.
READ MORE: State Dept: US Diplomats in Cuba Getting Medical Exams Following Sonic Attack
