Shares in Apple have fallen for the 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 percent, or almost $200 billion, in the past two days.

China is the technology giant’s third-largest market, accounting for 18 percent 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, WSJ, reported on Wednesday that Beijing had ordered central government agency officials not to 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 instructions not to use iPhones were given to officials by their superiors in recent weeks, sources told the WSJ. 

Restrictions were also placed on other foreign-branded devices.