Popular social networking site Facebook has gone down in a global outage, locking out more than one billion users across the world.
Instead of the usual log-in page, users were greeted with an error message: "We're working on getting this fixed as soon as we can."
Users in the United Kingdom, Israel and India were among those affected. The company acknowledged the problem, but has not revealed the cause or how many users were affected.
The outage affected all of the various means of using the site - both website and mobile apps - and lasted some 15 minutes this morning, in the UK, between approximately 9.15am and 9.30am. Users took to alternative social networks, such as Twitter, to complain.
The outage is surprising as Facebook has maintained exceptionally high levels of uptime, especially for a free web-based service. However, any prolonged outage will affect the companies advertising revenues - as well as many media sites which drive traffic via Facebook.
The company's data centres are located in the US, with its latest opened in the past 18 months in Sweden - with more planned.