Lizard Squad, the hackers who this week knocked the website of Malaysia Airlines offline, have said they are behind a major attack on Facebook, Instagram and Tinder.
However the world's largest social network has claiming the outage was not the result of an attack by an outside group, but instead came from an internal fault. A statement by Facebook said:
Earlier this evening many people had trouble accessing Facebook and Instagram. This was not the result of a third party attack but instead occurred after we introduced a change that affected our configuration systems. We moved quickly to fix the problem, and both services are back to 100% for everyone.
The hackers earlier claimed responsibility through the group's Twitter account @LizardMafia:
Facebook was knocked offline around the world for most users for an hour from 6.10am GMT on Tuesday morning (27 January), with millions of people unable to access the network either through the browser or one of the company's smartphone or tablet apps.
Tinder, the matchmaking mobile app, also experienced problems, with the company's official Twitter account confirming it was suffering from an outage:
"More to come"
Facebook's outage was obviously the most high profile considering the company has 1.35 billion users around the world, and according to the information from the website DownRightNow, the social network has been suffering from intermittent problems for the last 12 hours.
A map of the reports from DownDetector suggest the problem was a global one, with most reports focused in the US and Europe.
Lizard Squad are a group of rogue hackers who shot to fame in December when they knocked the PlayStation Network and Xbox Live offline for a sustained period of time over Christmas.
Since then the group has begun selling a tool called LizardStresser which is a DDoS tool allowing willing parties to pay to knock another individual or business offline. The group uses its own attacks to promote the tool.
Since the attacks on PSN and Xbox Live in December, authorities in the US and UK have been carrying out a major investigation resulting in several arrests in the UK in recent weeks.
On New Years' Eve a 22-year-old from Twickenham was arrested on suspicion of fraud by false representation and Computer Misuse Act offences, and is scheduled to appear in court again on 10 March.
Last week, a teenager from Southport near Liverpool was arrested in relation to the attacks on PSN and Xbox Live, as well as so-called swatting offences - the term used to describe the act of knowingly providing false information to law enforcement about a target.
In an interview last year, the Southport teenager claimed that Lizard Squad had up to 15 members.