Scores of London flights are disrupted today after an extraordinary air traffic shutdown across the US sparked travel chaos.

The US Federal Aviation Administration (FAA) grounded all flights nationwide for about four hours on Friday “due to extraordinary circumstances and for reasons of safety” following communications problems at regional air traffic control centres.

About 10,000 flights to and from the US have been cancelled, according to Flightradar24, following the longest US air traffic shutdown since the 9/11 attacks.

US transportation secretary Sean Duffy announced shortly after 1.30am GMT that the airspace had reopened, but said disruption would continue for a number of days.

The extraordinary ground start began to impact London flights on Friday night, British Airways cancelling a flight to New York which had been due to take off from Heathrow at 10.30pm on Friday.

At 6.45am on Saturday, Heathrow’s website was showing 29 cancelled flights to and from the US with delays to 19 departures.

At Gatwick, three flights scheduled to arrive from Orlando in Florida at 7.30am were cancelled.

The UK Civil Aviation Authority has warned of “follow-on disruption” to passengers.

Tim Johnson, consumer director at the UK Civil Aviation Authority, said: “While US flights have resumed, there may be some follow-on disruption as airlines work to re-book affected passengers and get all services back to normal.

“Anyone due to travel on flights between the UK and USA should check with their airline for the latest information before heading to the airport.

“We know that UK airlines are doing all they can to minimise inconvenience and to make sure their customers are properly looked after.”

Responding to customers on X, British Airways apologised for possible delays and cancellations.

It also recommended passengers travel to the airport as planned to arrive for the original departure time, unless informed otherwise.

A British Airways spokesperson said: “Our flights departing the United States may be delayed due to the ongoing air traffic control issue.

“Customers are advised to travel to the airport as planned so we can try to depart our aircraft as quickly as possible.

“This is entirely outside of our control and our teams are working hard to minimise any disruption to our customers.”

Virgin Atlantic said a flight from London Heathrow to New York JFK that was scheduled to leave on Friday had been cancelled.

A Virgin Atlantic spokesperson said: “We’re aware of the ground stop order issued by the Federal Aviation Administration for all US airports.

“We’re closely monitoring the situation and assessing any impact to our flights. We advise any customers due to travel to check their flight status at virginatlantic.com.”

Late on Friday, Eurocontrol said all US-bound air traffic from its member states had been suspended amid the disruption in the US.

A statement on the organisation’s website said: “To the attention of all Aircraft Operators: On request of FAA due to technical issues all traffic departing within IFPZ (Eurocontrol member states) between 2200 UTC on 13 NOV and 0500 UTC on 14 NOV, bound for US airports is suspended.

“For more information check ATCSCC Advisory.

“NMOC (Network Manager Operations Centre) is closely monitoring the situation and will provide updates accordingly.”

Eurocontrol has 42 member states, including the UK, Ireland, Germany and France, as well as two agreement states – Israel and Morocco.

Homeland Security secretary Markwayne Mullin told reporters at the White House that the introduction of some new technology into an old air traffic control system overwhelmed it. He could not rule out another outage.

Mr Mullin added “it doesn’t appear” that a cyber attack or rogue artificial intelligence played a role in the incident.

Mr Duffy said he expected flights around the US to be “back up and operational as we come into the heat of travel” next weekend ahead of Thanksgiving, but he also suggested more disruptions might occur.

“We didn’t think we would have this kind of outage. We did,” he said.

“We were able to review what went wrong, and then reboot the system and go. But, you will have more of these.”