Facebook, Instagram and WhatsApp go down for about six hours

Facebook and Instagram, as well as the WhatsApp and Messenger apps, were unavailable worldwide for about six hours. It was the biggest outage in the company's history.

Facebook said the cause was configuration changes to routers that coordinate traffic between its data centres. As a result, the services effectively disappeared from the internet.

The failure also hit the company's internal systems: according to media reports, staff could not enter offices with their electronic passes. Facebook shares fell almost 5% on the day.

In Armenia, as in many countries, users flocked to Telegram and other messengers. Telegram reported more than 70 million new users in a single day.