Shares in Apple have fallen for a second day in a row after reports that Chinese government workers have been banned from using iPhones.
The firm's stock market valuation has fallen by more than 6%, or almost $200bn (£160bn), in the last two days.
China is the technology giant's third-largest market, accounting for 18% of its total revenue last year.
It is also where most of Apple's products are manufactured by its biggest supplier Foxconn.
The Wall Street Journal reported on Wednesday that Beijing had ordered central government agency officials to not bring iPhones into the office or use them for work.
The following day, Bloomberg News reported that the ban may also be imposed on workers at state-owned companies and government-backed agencies.
The reports came ahead of the launch of the iPhone 15, which is expected to take place on 12 September.
There has been no official statement from the Chinese government in response to the reports.
Apple has the world's highest stock market valuation, standing at close to $2.8 trillion.
The company did not immediately respond to a BBC request for comment.
Shares in some of Apple's suppliers have also fallen.
Qualcomm, the world's biggest supplier of smartphone chips, dropped by more than 7% on Thursday.
Shares in South Korea's SK Hynix were around 4% lower on Friday.
The reports came as tensions between Washington and Beijing remain high.
This year, Washington, along with its allies Japan and the Netherlands, restricted China's access to some chip technology.
China retaliated by restricting exports of two materials key to the semiconductor industry.
Beijing is also reportedly preparing a new $40bn investment fund to boost its chip making industry.
Last week, during US Commerce Secretary Gina Raimondo's visit to Beijing, Chinese tech giant Huawei unexpectedly unveiled its Mate 60 Pro smartphone.
On Friday, the company launched presales of the Pro+ model of the phone.
Canada-based technology research firm, TechInsights, said the phone contained a new 5G Kirin 9000s processor, developed for Huawei by China's largest contract chipmaker SMIC.
TechInsights analyst Dan Hutcheson said it "demonstrates the technical progress China's semiconductor industry has been able to make".
This is a "big tech breakthrough for China," investment firm Jefferies said in a research note.
This week, US congressman Mike Gallagher, who is the chairman of the House of Representatives committee on China, called on the Commerce Department to further restrict exports to Huawei and SMIC.