The U.S. Embassy in China issued an alert to Americans Friday to seek medical attention if they experience symptoms consistent with the mysterious sonic attacks that have affected staffers in China and Cuba.

“Symptoms to be attentive for include dizziness, headaches, tinnitus, fatigue, cognitive issues, visual problems, ear complaints and hearing loss, and difficulty sleeping,” the warning stated.

After the incident occurred at the Guangzhou consulate in May, the State Department said it is taking the reports seriously and informed its staff in China.

State Department spokeswoman Heather Nauert also said at the time that the Chinese government assured the State Department that it is investigating the symptoms felt by the U.S. government employee.

Since the incident, other employees from the consulate and their families have been evacuated. There is a U.S. medical team in Guangzhou assessing whether more people need to leave China, the Associated Press reported.

The “sonic attacks” on American personnel in Cuba resulted in severe hearing loss for some. The Cuban government denied involvement in the attacks and the State Department sent more than 60 percent of Americans working at the U.S. embassy there home.

Following the Havana attacks, the FBI launched a year-long investigation that ultimately could not answer what caused the phenomena. Medical experts and the FBI are still in the dark on the mysterious illness.

  China, Cuba, FBI, Federal Bureau Of Investigatio, n Foreign Policy, State Department