Global social media giant Facebook has apologised for any inconveniences experienced by its billions of users after a worldwide outage left the platform and many of its subsidiaries inoperable for several hours.

Earlier today (Tuesday 5 October) news surfaced that Facebook and many of its other apps, including WhatsApp, Instagram and Oculus, were displaying error messages and not working.

Facebook responded to these concerns, claiming the issue was being looked into and would get everything back online as soon as possible.

However, it was later reported by the New York Times that Facebook employees themselves were also directly affected by the outage, with them being unable to enter the headquarters because their badges weren't working.

Around half an hour ago (9.30am on 5 October), the company issued a statement on rival platform twitter announcing its services were beginning to come back online and apologised to its user base for the outage.

"To the huge community of people and businesses around the world who depend on us: we're sorry," the statement said.

"We’ve been working hard to restore access to our apps and services and are happy to report they are coming back online now. Thank you for bearing with us."

At this point, the cause of the outage has not been confirmed by Facebook, though the company's Chief Technology Officer earlier mentioned "networking issues" in a tweet apologising to users, while technology experts revealed Domain Name System (DNS) records, which tells systems how to find website URLs like Facebook or Instagram, had been withdrawn.