WhatsApp went down for a brief period on Wednesday morning as users in India and worldwide were unable to send or receive messages for couple of hours.
The app would still open but a connecting loop was displayed while the service experienced issues.
The service was later restored.
A Facebook spokesperson told The Verge: "Earlier today, an internal update made to our WhatsApp servers caused some people to have trouble sending messages.
"We quickly resolved this issue for everyone and we apologise for any inconvenience".
Affected users found that WhatsApp was "connecting" when trying to send a message.
WhatsApp went down on June 19 for millions of users in India and elsewhere who reported issues with privacy settings as well as last seen online status not working.
According to outage monitor portal Down Detector, there was a 66 per cent spike in WhatsApp down reports, with last seen online status not working for them as well as 28 per cent reporting connection issues.
Both Android and iOS WhatsApp users took to Twitter to report the issues.
On June 16, Facebook, Messenger and Instagram suffered outages in various parts of the world, and Instagram users were not able to post direct messages.
WhatsApp now has 2 billion users globally and India has over 400 million users.