For months, American officials have been anxious diplomats have been subjected to targeted attacks involving odd sounds, leading to symptoms similar to those "following concussion or minor traumatic brain injury", the State Department says.
State Department spokeswoman Heather Nauert said those evacuated would undergo further medical assessments at the University of Pennsylvania.
"As for the latest incident, my understanding is that the USA side hasn't had any formal communication with the Chinese side about it", foreign ministry spokeswoman Hua Chunying said at a regular press briefing.
Canada said the 10 people continued to show unexplained brain symptoms and that 'medical information raised concerns for a new type of a possible acquired brain injury'.
Friday's alert called for people to be attentive of symptoms including "dizziness, headaches, tinnitus, fatigue, cognitive issues, visual problems, ear complaints and hearing loss, and difficulty sleeping".
Vehicles pass by high-rise apartment buildings in The Canton Place where USA government workers experienced unexplained illnesses.
A Chinese government investigation has shed no light on why a US diplomat fell ill at the consulate in Guangzhou after hearing mysterious sounds, an official said Thursday. Pompeo said then that the employee's symptoms were eerily similar to those reported by the Cuban embassy staff.
The latest round of evacuations, which began Wednesday in China, was the first sign that the unexplained ailments have now broadened and threaten to become a full-blown health crisis like the one that affected at least 24 diplomats and their families in Cuba.
The Penn team said the patients from Cuba experienced persistent disability though rehabilitation therapy customized for them seemed to help. The Chinese have never been shy about making sure American diplomats knew they were under constant monitoring - though before now, the most aggressive tales involved State Department officials returning home to find someone had defected in their toilet and left it without flushing.
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.
Last year, 24 USA diplomats and their family members in Cuba fell victim to mysterious "attacks" that left them with injuries resembling brain trauma.
The US embassy in China has issued a new alert over a mystery illness affecting some of its diplomats.
The State Department acknowledged the Lenzi incident late last month. The Guangzhou consulate opened months after the establishment of diplomatic relations between Beijing and Washington in 1979 and moved to its new purpose-built facility in 2013. "This does not fit with China's basic concept and principles of diplomacy, and is inconceivable", the Global Times said in an editorial.
'Hard to get my head around how it works, ' he said.
"For me I feel it's very unusual".