A radar glitch forced the temporary closure of London airspace for 36 minutes on Wednesday, triggering widespread delays and disruptions expected to affect major airports across Europe.

Passengers flying to or from the UK, or transiting through London, are being warned of potential cancellations and delays after air traffic authorities shut down the capital’s airspace due to what they described as “technical issues” stemming from a “radar failure.”

“The London control area is temporarily unavailable due to technical issues,” said Eurocontrol, the EU-wide air traffic control organization. It emphasized that the radar failure appeared to be an isolated incident within the UK, with no impact reported in continental Europe.

Shortly after, NATS—the UK’s air traffic control provider—confirmed via X (formerly Twitter) that the issue had been resolved.

“We thank passengers for their patience while we work to return to normal operations. Please continue to check with your airline for the latest information on your flight,” NATS said in a statement.

According to media reports, some departures were halted for up to 60 minutes, with British Airways particularly affected. The airline said the issue had impacted the “vast majority” of its flights.

Delays are now expected at several major European hubs, including airports in Amsterdam, Paris, and Brussels, due to the ripple effect of the London closure.

Data from aviation analytics firm Cirium, cited by The Telegraph, indicated that UK airports were scheduled to handle 3,080 departures on Wednesday.