The attacks involved strange sounds of unknown origin and have left Embassy staff sick, sometimes with serious consequences. US and Cuban investigators still haven’t determined the source of the attacks, according to officials.
Although no American travelers have been harmed, the US government said in the warning issued on Friday that "because our personnel's safety is at risk, and we are unable to identify the source of the attacks, we believe US citizens may also be at risk and warn them not to travel to Cuba."
The decision doesn’t end US diplomatic relations with Cuba, which were restored in late 2014. However, the embassy is losing more than 60 percent of its personnell and will stop issuing visas in Cuba effective immediately.
This update follows the travel warning for Cuba issued on September 13 following Hurricane Irma. US citizens in Cuba still in need of emergency assistance shouldn't attempt to go to the U.S. Embassy Havana at this time as it suffered severe damage, but instead contact the Embassy or Department of State by telephone.
See the State Department’s travel website for the Worldwide Caution, Travel Warnings, Travel Alerts, and Country Specific Information for Cuba.
