Major websites across the world suffered outages on Tuesday morning.
A number of leading news websites including the Evening Standard, The Independent, the New York Times, The Financial Times, The Guardian and CNN were affected.
Early reports suggested the issues could be related to Fastly, a cloud computing provider.
The UK government website - gov.uk - was also affected, as was Amazon, Reddit, Twitch and Pinterest.Affected websites displayed the message: “Error 503 Service Unavailable.”
Alex Hern, the Guardian's technology editor, tweeted that Fastly "has been identified as the cause of the problem".
"The outage, which began shortly before 11am UK time, saw visitors to a vast array of sites receive error messages including 'Error 503 Service Unavailable' and a terse 'connection failure'," he tweeted.
The Quartz site has also attributed the issue to Fastly via Twitter.
Websites affected by the outage appeared to gradually come back online by the afternoon, but loading times were reported to be slow.
Fastly, which has been widely reported as the source of the problem, updated its service status page, saying: “The issue has been identified and a fix is being implemented.”
But the issue reported to be behind the global internet outage was probably due to a physical issue rather than software related, a software testing expert has told the PA news agency.
“Given the nature of this kind of technology, it’s probably not a software issue,” said Adam Leon Smith, from BCS, The Chartered Institute for IT.
“It’s more likely to be a physical issue or a hardware failure somewhere.”
He added: “Some of the websites will have removed their dependency on Fastly in order to get themselves back online and so I think within a few hours things should be ticking along nicely again.”
