An airport computer glitch has meant some air passengers have still not been reunited with their luggage days after a problem started.
The glitch began on Thursday at Heathrow's Terminal 5 (T5) and has affected departing British Airways passengers.
Some of these travellers had to fly without their hold luggage and although normal baggage check-in has resumed at T5, not all the affected passengers have got their bags yet.
T5 had a disastrous opening in March 2008 when thousands of bags went missing and there were long delays and cancellations.
A Heathrow spokeswoman said today: "We experienced intermittent issues with the T5 baggage system between June 26 and 29 which caused some bags to be processed manually. Passengers can now check in bags as normal.
"Manual processing led to some bags not making flights in time. While passengers are receiving bags all the time, it will take several days to reunite all passengers with their bags.
"We are very sorry for the disruption passengers have experienced and we are working round the clock with airlines to reunite passengers with their bags as quickly as possible."
A British Airways spokesman said: " We have been working round the clock to reunite customers with their bags since the airport's baggage system in T5 first started experiencing IT faults last Thursday morning.
"We are very sorry that this process is taking longer than anticipated, and we fully understand the frustration that this is causing."
He went on: " Although we have not been able to use T5's baggage system to its full capacity to manage delayed bags for the past four days, we have used a range of other methods to process bags and are hoping that the last remaining items will depart from Heathrow by the end of today.
"Given the nature of global travel and a range of complex security and customs regulations in some countries, it may take several more days to reunite bags with their owners.
"Our flights at T5 are operating normally and customers can check in bags as usual, although we would continue to advise that essential items are carried in hand baggage."