Facebook and its WhatsApp and Instagram apps have suffered an outage and users of the social media sites around the world appear to be affected.
Photo: Pixaby
Facebook said it was aware that some people were having trouble accessing company's apps and products.
Instagram, owned by Facebook, also stopped working and the company tweeted it was aware users were having issues.
Facebook was inaccessible because users were not being directed to the correct place by the Domain Name System. Facebook itself controls the relevant settings.
DNS allows web addresses to take users to their destinations. A similar outage at cloud company Akamai Technologies Inc took down multiple websites in July.
Security experts tracking the situation said the outage was likely to have been triggered by a configuration error that left directions to Facebook servers unavailable. That could be the result of an internal mistake, though sabotage by an insider would be theoretically possible.
An outside hack was viewed as less likely. A massive denial-of-service attack that could overwhelm one of the world's most popular sites, on the other hand, would require either coordination among powerful criminal groups or a very innovative technique.
Facebook's response was made much more difficult because employees lost access to some of their own tools in the shutdown, people tracking the matter said.
The company acknowledged users were having trouble accessing its apps but did not provide any specifics about the nature of the problem or how many were affected by the outage.
Downdetector, which only tracks outages by collating status reports from a series of sources, including user-submitted errors on its platform, showed there were more than 50,000 incidents of people reporting issues with Facebook and Instagram. The outage might be affecting a larger number of users.
Facebook's instant messaging platform WhatsApp was also down for over 35,000 users, while Messenger was down for nearly 9800 users.
Facebook has experienced similar widespread outages with its suite of apps this year in March and July.
Several users using their Facebook credentials to log in to third-party apps such as Pokemon Go and Match Masters were also facing issues.
Some people also reported problems using Facebook's virtual reality headset platform, Oculus, the BBC reported
Several other tech companies, including Reddit and Twitter, have poked fun at the social media giant's predicament - prompting responses from the affected apps.
Facebook shares fell 5.5 percent in afternoon trading on Monday, inching towards its worst day in nearly a year.
In recent months many high-profile denial of service attacks have hit companies worldwide including banks and government agency sites in New Zealand.
- RNZ / Reuters / BBC