LONDON (AP) — British Airways canceled dozens of flights from Heathrow Airport on Saturday as it struggled to fix “technical issues” that hobbled booking and check-in systems.

The airline canceled all short-haul flights from the airport until midday. It said there would likely be delays to long-haul flights and there was likely to be “further disruption during the day” at Heathrow, Gatwick and London City airports.

BA advised customers to check the website for the latest flight information before heading to airports.

The airline said the problems were caused by a hardware issues and not a cyberattack.

BA’s website and app were inaccessible for hours on Friday evening, preventing customers from checking in online or booking flights.

Several times in the past few years BA has experienced problems with its check-in systems that saw hundreds of flights canceled and thousands of people stranded.

Paul Charles, chief executive of travel consultancy The PC Agency, said “ongoing technical issues don’t fill consumers with much confidence.”

“BA needs to be transparent on what’s causing these issues and how soon they will be fixed,” he said.