Editors' pick: Originally published Nov. 15.

The China Consumers Association (CCA) has asked Apple (AAPL) - Get Report to investigate into a sudden shutdown problem associated with iPhone 6 and iPhone 6s in China.

A statement released by the consumer protection organization said it has received a considerable number of complaints from users of both devices reporting that the smartphones have been shutting off automatically without being able to be turned back on.

The stated problem involves models of 6 and 6s iPhones shutting down automatically while on a 50%-60% battery level. The sudden shutdown often happens after a system upgrade and when in a room temperature or colder environment. What particularly frustrates users is that the devices often cannot be turned back on after the involuntary shutdown despite continuous battery charging.

In an official statement issued to Apple, the CCA asked the company to find out whether the problem has anything to do with the cellphone batteries and Apple's planned measures if the problem escalates. The CCA demands an answer from Apple within 10 days.

According to its latest 10k filing, Apple's overall sales declined by 30% year over year in the Greater China region for its fiscal 2016 fourth quarter ended Sept. 24, 2016. The decrease during 2016 compared to 2015 is primarily due to lower net sales and unit sales of iPhones and the effect of the depreciation of the Chinese currency against the U.S. dollar.

The Cupertino, Calif., company also guided to fiscal-first-quarter gross margins of 38% to 38.5% verses 39% consensus.

"The company is a victim of its own success from the iPhone 6 and 6 Plus rollout in the region, where the upgrade rate increased relatively higher than elsewhere around the world, creating tough compares throughout this year," wrote Jack Mohr TheStreet's chief investment officer in an Action Alerts PLUS note to subscribers on Oct. 25. "That being said, management is confident Apple is returning to growth this quarter and they remain focused on the region given the inherent opportunity as the middle class grows and LTE adoption rates remain low."

Apple's main smartphone rival Samsung Electronics had a global recall of around 2.5 million of its flagship Galaxy Note 7 phones in October due to their tendency to catch fire and explode. The company pointed out "a battery cell issue" as the likely root cause for the combustion.

Apple has also been in the headlines recently regarding China due to President-elect Donald Trump's campaign promise to label China as a currency manipulator and slap steep tariffs on Chinese imports. An op-ed from state-owned newspaper Global Times on Sunday said that "iPhone sales in China will suffer a setback" if those promises are carried through.

Apple did not respond to a request for comment Tuesday.