A computer problem affecting the automated passport control system caused long delays on Saturday for travelers arriving at UK airports.

On social media, many travelers complained of having to wait hours before going through immigration control amid the long weekend.

London’s Heathrow and Gatwick airports have cited a nationwide problem affecting the UK Border Police’s electronic gates, which allow automatic clearance.

Additional staff were deployed to manage queues and assist passengers.

Early on Saturday evening, the British Home Office assured that the technical problem with the border system had been resolved.

“Following the technical failure in the border system which affected entries into the UK through electronic gates, we can confirm that all electronic gates are now operating normally,” the ministry said.

The UK has more than 270 e-gates across 15 infrastructures. These are available to travelers over the age of 12, whether they are British, EU citizens or other countries (including Australia, Canada, Iceland, Japan, the United States).

Long queues were reported on Saturday morning to board ferries at the English Channel port of Dover (south-east England) due to a computer problem at passport control at the French border.

That has been “resolved,” the port authority announced via Twitter, estimating wait times between 30 and 45 minutes at noon, compared with 90 minutes in the morning.

The problems come after British Airways was forced to cancel several flights — 175 according to Britain’s PA news agency — between Thursday and Friday due to a technical problem.