Heathrow Airport earlier warned passengers they might have to fly without their luggage today after a system failure.

In a tweet the airport advised passengers to pack only essential items in their hand luggage, but has now issued an update saying baggage check in desks are now open again.

British Airways and American Airlines were both affected as well as Spanish flag carrier, Iberia.

The IT outage comes just weeks after BA had to cancel all its flights from both Heathrow and Gatwick after an IT disaster hit its computer systems.

A spokesman for the airport told the BBC hold bags will follow passengers but they could not say when.

Are IT failures becoming more common?

There have been some very high profile outages recent, most notably the WannaCry hack that hit the NHS and the BA systems outage.

While these have different causes, with BA ruling out a cyber attack for its outage, customers and service users are still disrupted.

As organisations increasingly rely on outdated and ageing software and computers the risk of failures rises, while hackers who could be state-sponsored or attempting ransom are becoming more sophisticated.

What will it cost the airport?

The exact cost is so far unknown but if the problem is contained it is unlikely to be as costly as the recent BA outage.

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BA is thought to be facing a bill of around £100m in terms of compensation, refunds, rebooked flights and additional staffing and related costs.

Read more: British Airways or Indian outsourcer? Who’s to blame for 300,000 stranded passengers

However, the reputational damage that BA will suffer will run to much more and Heathrow will be looking to avoid that.

The Heathrow outage comes as the debate around which London airport should be granted expansion rights continues to roll out, despite a parliamentary committee backing Heathrow.