Oct. 6 (UPI) -- U.S. civilians visiting Cuba have reported symptoms similar to those experienced by U.S. diplomatic workers allegedly targeted in a mysterious attack at the the U.S. Embassy in Havana, State Department officials said Friday.
U.S. citizens not working for the government are reporting similar symptoms to what at least 22 U.S. diplomats experienced at the embassy and other locations in the city. Those symptoms include mild traumatic brain injury, permanent hearing loss, loss of balance, headaches and brain swelling.
"A handful of U.S. citizens who recently traveled to Cuba have communicated to us that they experienced symptoms similar to those listed in our Sept. 29 travel warning," a State Department official told ABC News. "We cannot verify the claims and continue to urge American citizens to review our travel warning prior to traveling to Cuba."
CBS News confirmed the details.
On Friday, the State Department issued a new advisory, urging U.S. citizens who have traveled to Cuba to report any symptoms they may have experienced. A news release said the department "imposed limitations" on two hotels, where the so-called acoustic attacks have taken place: Hotel Nacional and Hotel Capri.
On Sept. 29, the United States pulled all non-emergency staff from the embassy in Havana.
"Until the government of Cuba can ensure the safety of our diplomats in Cuba, our embassy will be reduced to emergency personnel in order to minimize the number of diplomats at risk of exposure to harm," the State Department said at the time.
Cuban officials have denied any involvement in the incidents.
"The Cuban government has never perpetrated nor will it ever perpetrate attacks of any kind against diplomats," the Cuban Foreign Ministry said.