Flurries of panicked posts have been made on Twitter
Popular messaging service WhatsApp suffered an outage tonight, leaving millions of users in the lurch.
From around 9pm Irish time, the app has been unable to connect to online servers and people have been unable to send texts, images or anything else using the service.
It is unclear what the problem is, or when connections will be restored.
Thousands of reports flooded in to downdetector.co.uk, where users have written of outages across the UK and parts of Europe.
Flurries of panicked posts were also made on Twitter.
It appears as though the Facebook-owned app had been planning an update due to go out this evening.
It has been reported the firm was going to introduce a feature that would allow users to 'pin' a conversation to the top of a list within the app.