The State Department issues a health alert for all of China after USA diplomats and staff members began suffering from a sound-related illness.
Cuba said on Sunday it remained baffled by health issues affecting U.S. diplomats, after the U.S. State Department reported two Cuba-based functionaries had symptoms similar to previous cases that began in late 2016.
The two individuals are considered "potentially new cases" but have not yet been "medically confirmed", a State Department official said.
A US medical team has been screening more personnel and their family members who work in Guangzhou this week in order to determine who may have been affected.
The US is testing two staff members from its Cuban embassy in Havana amid concerns they may have been subjected to sonic attacks.
The Chinese foreign ministry said Thursday that its investigation into the first case has not yielded any clues as to the cause of the incident.
The evacuated Americans have been transferred to the same facility at the University of Pennsylvania where the government workers in Cuba were sent, an unnamed US official told The Associated Press.
It warned of "unexplained physical symptoms or events, auditory or sensory phenomena", and said symptoms of the ailment included dizziness, headaches, tinnitus, fatigue, cognitive issues, visual problems, ear complaints, and hearing loss, as well as difficulty sleeping.
Asked about the latest incidents, Chinese Foreign Ministry spokeswoman Hua Chunying said Thursday that the USA had not formally raised the matter with Beijing.
The Cuba incidents sparked concerns that the employees had been targeted with some novel sort of sonic attack, and similar reports this week in Guangzhou, China, have prompted several evacuations of diplomats and family members.
A security person walks outside the USA consulate building in Guangzhou in south China's Guangdong province, Thursday, June 7.
If confirmed by doctors to have the same condition, the two individuals would mark the 25th and 26th confirmed patients from the freakish incidents in Cuba that were first disclosed past year and have been deemed "specific attacks" by the US government. The AP reported that out of the approximately 170 American staffers in the consulate, 150 have undergone the examinations.