Some WhatsApp users as from today could find themselves unable to use the app as the technology stops running on older phones.
Mobiles affected by changes in technology are BlackBerry (pictured), including BlackBerry 10; Nokia S40; Nokia Symbian S60 (pictured); Android 2.1 and Android 2.2; Windows Phone 7 and iPhone 3GS/iOS 6.
The popular app will stop working on those mobiles.
This means users of such mobiles will be forced to upgrade their handsets if they want to continue using the service.
Recall the messaging app announced earlier last month that it will no longer support a range of older operating platforms by the end of the year. Among them are also iPhone 3GS and Windows Phone 7.
WhatsApp in the announcement said it will be phasing out support for older Windows, Android, and Apple models by January, with the service set to end for Blackberry users and Nokia models by mid-2017.
A blog post by the Facebook-owned app, said the older smartphone platforms can no longer keep up with the latest features being rolled out for the app.
And by June 2017, WhatApp will no longer be available for BlackBerry, including BlackBerry 10; Nokia S40; and Nokia Symbian S60.