A "technical issue" has hit UK air traffic control systems, with airlines warning of long delays to flights as engineers work on trying to resolve the problem.

The UK’s National Air Traffic Services (NATS) said it had "applied traffic flow restrictions to maintain safety" across its airports. They did not provide any further information about what caused it or how long it would take to fix.

“Engineers are working to find and the fix the fault. We apologise for any inconvenience this may cause,” NATS said in a statement.

“We are continuing to work hard to resolve the technical issue. To clarify, UK airspace is not closed, we have had to apply air traffic flow restrictions which ensures we can maintain safety,” it later updated.

The NATS describes itself as the country's leading provider of air traffic control services, which handles 2.5 million flights and 250 million passengers in a "normal year".

British Airways said it was working with NATS to "understand the impact" of the issue, and said it will keep customers updated. Other airlines are also asking customers to check for updates.

Scottish airline Loganair was the first to report a "network-wide failure of UK air traffic control systems this morning".

The disruption comes on one of the busiest travel days of the year — with many people returning from holidays on the last Bank Holiday weekend of the summer.

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