The iOS 10.2.1 update has reduced the chances of unexpected shutdowns that some of the iPhone 6 and 6s users were experiencing, according to Apple.

The update made available to iPhone 5 and later, iPad 4th generation and later, iPod touch 6th generation and later bundles bug fixes and improves the security the devices. The iOS 10.2.1 was released on 23 January.

Some of the iPhone models such as iPhone 6, 6 Plus, 6s and 6s Plus were facing unexpected shutdowns. The devices would suddenly go dark, forcing the users to plug in their device to power source to turn them on.

Without revealing the details on how widespread the shutdown problem was, in a statement issued to TechCrunch, Apple said only "a small number of users" were experiencing with their iPhones. It said iOS 10.2.1, which contains improvements to reduce the unexpected shutdowns, is running on more than 50% of devices.

"iOS 10.2.1 already has over 50% of active iOS devices upgraded and the diagnostic data we've received from upgraders shows that for this small percentage of users experiencing the issue, we're seeing a more than 80% reduction in iPhone 6s and over 70% reduction on iPhone 6 of devices unexpectedly shutting down," Apple told TechCrunch.

Through the update, Apple has also added the ability to restart the phone without connecting it to power if the unexpected shutdown occurs. It said the shutdown is not related to any safety issue, "but we understand it can be an inconvenience and wanted to fix the issue as quickly as possible. If a customer has any issues with their device they can contact AppleCare."