IT outages are reported across the world, affecting airlines, media, and banks
Airlines and airports have reported issues, with many flights grounded
The cause is not known - but Microsoft says it's taking mitigation issues
In the UK, railway companies say they're experiencing "widespread IT issues"
Sky News has not been able to broadcast live, its executive chairman says
The London Stock Exchange is also experiencing outages
Image source, Sky NewsA screengrab of Sky News Channel as of 08:10BST
In the UK, Sky News channel is off air due to the outages.
The channel has not been able to broadcast live this morning, the company's executive chairman says.
Several airports and airlines have reported issues with their IT systems.
Berlin airport posted on X, external that is experiencing delays to check-ins due to a "technical fault".
In Spain, an "incident" has been reported at all of the country's airports.
"We are working to solve it as soon as possible. Meanwhile, operations are continuing with manual systems," the Spanish airport operator says.
A major train company has warned passengers to expect disruption as it is suffering "widespread IT issues".
All four of Govia Thameslink Railway's brands - Southern, Thameslink, Gatwick Express and Great Northern - posted on social media: "We are currently experiencing widespread IT issues across our entire network.
"Our IT teams are actively investigating to determine the root cause of the problem.
"We are unable to access driver diagrams at certain locations, leading to potential short-notice cancellations, particularly on the Thameslink and Great Northern networks.
"Additionally, other key systems, including our real-time customer information platforms, are also affected.
"We will provide additional updates when we can. In the meantime, please regularly check your journey before you travel."
Microsoft says it is taking "mitigation actions" after service issues, AFP news agency reports.
It says its outage started at about 18:00 ET (0000 BST) on Thursday.
The company says it is investigating issues with cloud services in the US, and an issue impacting several of its apps and services.
Major banks, media outlets and airlines are currently suffering major IT outages.
Flights have been grounded at Sydney airport, United Airlines has stopped flying, and the London Stock Exchange group’s platform is experiencing outages.
Stay with us as we bring you all the latest news on this developing story.