All luggage check-in has been suspended at Heathrow's new £4.3bn Terminal 5, after cancelled flights and baggage delays blighted its opening day.
Flights from Heathrow's new £4.3bn Terminal 5 are departing with hand baggage only after luggage check-in was suspended due to technical problems.
British Airways, which has sole use of the terminal, cancelled 34 flights due to "teething problems" and was later forced to stop luggage check-in.
On a day of glitches, British Airways, which has sole use of the terminal, announced check-in of all hold luggage would be suspended on Thursday evening.
Technical difficulties have also led to baggage delays of up to four hours.
The airline has already cancelled 34 flights and further technical problems have led to long baggage delays.
BA blamed the glitches on problems with "staff familiarisation", which had a knock-on effect on bags and flights.
BA said it "sincerely" apologised to all those customers affected.
The computer cannot cope with the number of bags going through Baggage worker
Announcing the suspension of baggage check-in, Gareth Kirkwood, BA's director of operations, said: "We sincerely apologise to those customers who have suffered disrupted journeys or baggage delays.
In a day of problems at the new terminal, airport operator BAA said a baggage belt had stopped working, meaning a halt to check-in for passengers with bags.
"We always knew the first day would represent a unique challenge because of the size and complexity of the move into Terminal 5. We are working extremely hard on solutions to these short term difficulties."
One baggage worker told the BBC the situation was "mayhem" and that the technical problems had been known about for some time.
The airline is advising passengers to check in with hand baggage only if they wish to travel later, or to telephone BA if they want a refund or to rebook a flight.
"They have been doing tests on the belt system for the last few weeks and knew it wasn't going right. The computer cannot cope with the number of bags going through."
BA earlier blamed the glitches on problems with "staff familiarisation", which had a knock-on effect on bags and flights.
Staff screening
BA issued an information line for T5 passengers: 0800 727800
A BA spokeswoman said delays in getting staff screened for work and other technical difficulties had caused the airline problems at the start of the day and continued to have a knock-on effect.
The company warned more flights could be cancelled as a result of the latest glitch.
Cancelled services in and out of the terminal so far have included flights to Munich, Frankfurt, Paris and Brussels as well as Glasgow and Aberdeen.
Passengers departing from and arriving at the new terminal have also suffered delays retrieving their bags.
Departures and arrivals ... what do passengers think of the new Heathrow terminal?In pictures
Some waited two hours for luggage from a Frankfurt flight that landed at around 0830 GMT.
And in Paris, BBC reporter Peter Grant said no bags had made it on to his morning flight from Heathrow.
Airport operator BAA, which operates the baggage distribution system at T5, said a total of seven flights had left the terminal without luggage on board due to a system fault.
Danish businessman Henrik Moeller, who travelled from Hamburg and landed at T5 at 0745 GMT, said he was not reunited with his bags until 0900 GMT.
"I have read about this new bag system and how it was supposed to be so much better. It's obvious there have been teething problems."
Anja Kaut, arriving from Munich with her husband Matthew and 10-year-old daughter, Charlotte, also had to wait about an hour for their luggage.
"We were told there was a technical defect," said Mrs Kaut.
System fault
But those departing also suffered problems.
Heather Stevens's partner Neil Stonebridge was due to take off from T5 for Los Angeles at 1005 GMT. Almost three hours later the plane was still waiting for passengers' baggage to be loaded.
BA TERMINAL CHANGES 27 March: Domestic and most European flights move from Terminal 1 to T527 March: Long-haul flights from Terminal 1 move to T527 March: Miami service moves from Terminal 3 to T530 March: Algiers moves from Gatwick to T530 April: All Terminal 4 long-haul go to T5 (except Singapore, Bangkok and Sydney)17 Sept: Barcelona, Madrid, Lisbon, Nice and Helsinki move from Terminal 1 to Terminal 3Early 2009: Singapore, Bangkok and Sydney move from Terminal 4 to Terminal 3 Source: BA Heathrow upheaval
Heather, 36, told the BBC: "Apparently the computer software told the baggage people that the flight had taken off.
"So everyone in the plane just watched as all their suitcases were taken back into the terminal instead of being loaded on."
There were also complaints from passengers about confusing road signs, problems when paying at a car park, and broken down escalator.
One passenger in a wheelchair was stuck on a flight arriving into T5 from Glasgow for more than an hour - and then when he was transported to the terminal he realised he could not get up the kerb.
"I couldn't even get into the building without getting up a step," Matt Duffy told the BBC.
"It is totally unbelievable as far as I am concerned."
MP Alistair Carmichael has demanded an apology on behalf of all travellers affected by the T5 difficulties, blaming the airline's "inadequate operation" for the problems.
In a statement, BA said it had experienced "initial teething problems" first thing in the morning, which had caused delays in staff arriving at their posts.
Difficulties included car parking provision, delays in staff security screening and staff familiarisation and "some baggage performance issues", it said.
Environmental campaigners in red T-shirts staged a peaceful protest
"These delays have had a knock-on effect during the day so we have taken the decision to cancel a very small number of flights. We would like to apologise to passengers for any disruption to their flights," the statement added.
Earlier the company said such problems were "not unexpected following one of the most complex and largest airport moves in history".
Aviation analyst Jamie Bowden told the BBC such difficulties were to be expected on the opening of a terminal, with new airports in Japan and Hong Kong also suffering difficulties in their first days.
What was important was that BA and airport operator BAA worked together to solve the technical problems "quickly" to ensure the minimum disruption for passengers, he added.
Earlier, anti-airport expansion groups held a protest at the new terminal.
Hundreds of protesters - wearing Stop Airport Expansion T-shirts and opposed to plans for a third runway and sixth terminal at Heathrow - carried out a peaceful protest.
Have you been through terminal 5 today? What was it like? Do you work there? Tell us about the new terminal at Heathrow airport.
You can send pictures and video to: yourpics@bbc.co.uk or to send via MMS please dial +44 (0)7725 100 100.
Do not endanger yourself or others, take any unnecessary risks or infringe any laws.
