"We do not now know what caused the reported symptoms and we are not aware of any similar situations in China, either inside or outside of the diplomatic community", the United States diplomatic statement said.
The US government has held Cuba responsible, arguing that Raul Castro's authoritarian state must have either carried out the assaults or at least known who was behind them.
The State Department said in its Wednesday statement that anyone who experienced "unusual acute auditory or sensory phenomena" while in China should move away from the source of the noise. U.S. officials made no reference to Cuba, where similar reports have been made in relation to two dozen Americans, reports CBS News. The employee was stationed in Guangzhou in southern China.
United States diplomatic officials said they could not link the case to health issues suffered by U.S. government staff in Cuba dating back to late 2016.
Canada's Denis Shapovalov will face Rafael Nadal at Italian Open
The 24-year-old destroyed his racket in fury as he suffered his first loss to Fognini in three meetings, sinking 6-4 1-6 6-3 . However, Madrid finalist, Dominic Thiem was sent packing by Italy's Fabio Fognini in three sets 6/4, 1/6, 6/3.
U.S. Secretary of State Mike Pompeo testifies during a hearing before the House Foreign Affairs Committee May 23, 2018 on Capitol Hill in Washington, DC.
"The US government is taking these reports seriously and has informed its official staff in China of this event", it added.
Charles Rosenfarb, a doctor and director of the department's Bureau of Medical Services, said the symptoms were mixed, but consistent with brain trauma.
The US official at the consulate in Guangzhou experienced a variety of "physical symptoms" between late 2017 and April this year.
Pakistan condemns ex-PM Sharif over comment on attack on India
The Lashker-e-Taiba militant group, founded by US -wanted militant Hafiz Saeed, was blamed for the Mumbai massacre. The remaining two accused, Sharif's sons Hussain and Hassan Nawaz, have been declared absconders.
In Cuba, the us reported that some of its personnel and family members experienced a range of ailments, often after hearing an unusual sound.
At least 24 Americans who had worked or travelled in Cuba reported a range of medical symptoms beginning in November 2016, USA officials told CBS News past year.
An investigation to establish the cause and impact has been launched by the US State Department.
The United States previous year chose to withdraw a large number of embassy staff from Cuba after diplomats stationed there complained of symptoms such as hearing loss, dizziness, tinnitus, visual difficulties, headaches and fatigue.
Number of confirmed Ebola cases in DR Congo adds up to 14
Those exposed to the suspected Ebola cases will for the first time in Congo receive Ebola vaccinations, the health minister said. Salama also noted Mbandaka's proximity to neighboring countries, including Central African Republic and Republic of Congo.