Internet messaging service WhatsApp was down for thousands of users for about an hour across the world on Friday. Both Android and iPhone users were unable to send or receive messages. WhatsApp did not release an official statement, though the service was back for most users by the afternoon (in India).

Notably, this is not the first time that the Facebook-owned messaging service suffered an outage. In September as well as in May, users from many parts of the world had trouble accessing the app.

Till July, WhatsApp had over 1 billion daily users.

Nearly a thousand users from around the world had reported the app on Friday, according to independent website DownDetector, which tracks social comments around specific topics and monitors outages across the globe.

It did not take long for #WhatsAppDown to begin trending on Twitter, users’ preferred choice to check for an outage or complain.