WhatsApp was briefly down Tuesday, with users unable to send or receive messages on the Facebook-owned end-to-end encrypted messaging app.

Affected users may have seen that WhatsApp was “connecting” to the service when trying to send a message. The outage started at about 4 p.m. ET but appeared to be working again by 4:30 p.m. ET.

WhatsApp failing to connect to its servers. (Image Credits: TechCrunch)

When reached, a Facebook spokesperson confirmed the outage but didn’t divulge details.

“We’re aware that some people are currently having trouble sending messages and we’re working to restore WhatsApp for everyone as quickly as possible,” the spokesperson said.

WhatsApp hit the 2 billion user mark earlier this year. Facebook bought WhatsApp for $19 billion in 2014 in what became one of the social media giant’s biggest purchases.

Updated with comment from Facebook.