Major airlines have grounded flights across the US, citing communication issues caused by a global IT outage.
The outage – which has also affected banks and emergency services around the world – has been caused by a faulty software update from cybersecurity firm Crowdstrike.
Delta Airlines, which is the world’s second biggest carrier by passenger numbers, said all of its flights were paused. American Airlines grounded its flights earlier, but says it has now resumed service.
Crowdstrike has apologised and released a statement saying that the issue “has been identified, isolated and a fix has been deployed”. It is not currently known when the issue will be resolved.
Around the world, thousands of travellers have been affected. US tourist Stephanie Thompson was unable to board her flight back to Dallas following a holiday in the UK.
A spokeswoman for Los Angeles International Airport said the BBC that “some flights are taking off and landing”, indicating that the issue is primarily affecting airlines rather than airports.
United Airlines has also been affected by the tech outage, along with a number of smaller carriers.
The first indication of the Crowdstrike issue affecting US airlines emerged late on Thursday, when US airline Frontier said a major “technical outage” had affected its operations.
Globally, more than 1,300 flights have been cancelled.
