Apple's iOS 9: Customers report software upgrade crashes devices

Apple's roll out of its new iOS 9 operating system appears to have triggered technical difficulties for a number of customers, with many reporting that their devices had crashed after downloading it.

The update, which was made available just two days ago, was meant to improve efficiency and extend battery life.

But a number of users took to social media to flag issues, including problems installing the new software and frozen screens.

Some had been forced to return their devices to factory settings, losing any data that wasn't backed up.

Many vented their frustration on social media.

One Twitter post read: "Grrrr I thought updates were supposed to improve things not make them worse."

While another added: "It's called #IOS9, because it takes about 9 hours to finish installing."

While there were also plenty of posts in praise of the new system, analysts said any evidence of disatisifed customers was still significant, especially since it is not the first time the tech giant has suffered from technical glitches.