Unexplained sounds and vibrations that accompanied the symptoms initially led investigators to suspect a sonic weapon, although an interim Federal Bureau of Investigation report in January said no evidence had been uncovered that sound waves could have damaged the Americans' health, the AP reported.
"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.
CNN reported earlier this week a number of U.S. personnel in China have been sent back to the United States for further health screenings after concerns over reports of mysterious acoustic incidents similar to the Cuba "sonic attacks". The incident rattled U.S. -Cuba relations, but the occurrence of similar symptoms in China has raised suspicions about whether China, Russia, or another country might be to blame.
The two new individuals removed from Cuba were medically evaluated in just the past few weeks, two officials said.
A US State Department official has confirmed with Sputnik that two individuals from the US Embassy in Cuba are undergoing medical evaluations and may possibly be new cases in a string of mysterious illnesses that have struck diplomats at the diplomatic facility.
"The State Department received medical confirmation that a US government employee in China suffered a medical incident consistent with what other USA government personnel experienced in Havana, Cuba", the statement said, reiterating comments made last month by Secretary of State Mike Pompeo. It is also the only USA diplomatic installation in China authorized to process immigrant visas and handle adoptions. "Instead, move to a different location".
Cuba has denied targeting embassy staff, and the U.S. has not blamed the country's government for the suspected attacks.
Hua Chunying, spokesperson of the Ministry of Foreign Relations, recalled that from the first report on the mysterious sonic affection, studies were carried on and conclusions were presented to US authorities.
A security person walks outside the US consulate building in Guangzhou in south China's Guangdong province, Thursday, June 7.
It serves four southern provinces with a combined population of more than 204 million and processes more than 1 million visa applications of all types annually.
The medical screenings in China are continuing, Nauert said.
Linda Chen, who runs a coffee shop in the area, said she was mystified as to why only certain people seemed to have been affected in an area known for its comfort and safety.