• British Airways told customers on X it faced "baggage disruption" due to a fault at London Heathrow.
• Heathrow is Europe's busiest airport and the world's second-busiest for international flights.
• An aviation news site reported BA warned crews against checking bags due to the baggage system fault.

Some flight crews have been advised not to check bags amid a system fault at Europe's busiest airport, aviation news site Paddle Your Own Kanoo reported.

London Heathrow is also the world's second-busiest airport for international flights, behind Dubai, according to travel data provider OAG. On Wednesday, Heathrow announced that it's expecting its busiest-ever December after last month's 6.5 million passengers broke records for November travel.

Responding to customers who reported luggage troubles on Monday and Tuesday, British Airways' X account said the airline faced "baggage disruption" due to issues at Heathrow.

In another post, it said it was "unable to load a number of bags onto flights" on Monday "due to a fault with London Heathrow Airport's baggage system, which was out of our control."

PYOK reported that British Airways also told pilots and cabin crew not to check luggage due to the fault at Terminal 5.

It added that BA told crews the risk of reaching their destination without their bags was too high, and that they should pack essential uniform items and spare clothes in their carry-ons.

The report also said that, in an internal update on Tuesday, Heathrow Airport said that it was still working on "what can be done" to fix the fault.

Business Insider understands that as of Wednesday morning, British Airways passengers were no longer facing baggage issues.

British Airways did not comment when contacted by Business Insider. London Heathrow Airport did not immediately respond to a request for comment.