All flights leaving Terminals 1 and 2 at Manchester Airport have been cancelled after a power cut on Sunday morning.
“Passengers due to travel from Terminals 1 and 2 are advised not to come to the airport until further notice and to contract their airlines,” a statement from the airport said.
Manchester Airport also said arriving flights were being diverted to other airports, meaning people picking passengers up from the airport should check with airlines before setting out.
An Etihad Airways flight from Abu Dhabi's Zayed International Airport was diverted to Birmingham Airport.
A Singapore Airlines flight from Houston in the US had to go to Heathrow, while another, which came from Singapore, was sent to Gatwick.
Emirates, Etihad and Gulf Air operate services from Manchester's Terminal 1.
EasyJet, which also operates flights from Terminal 1, said there are “very long queues” for security, and disruption to baggage handling systems meant that passengers can only board flights with cabin luggage.
“Although outside of our control, we would like to apologise for any inconvenience experienced as a result,” the airline said.
“We are doing all we can and working closely with the airport team to minimise the disruption.”
Chris Woodroofe, the managing director of Manchester Airport, has said he is “really sorry” for the disruption.
Mr Woodroofe told BBC News a “fault with a cable had caused a power surge that took down security systems and baggage screening”.
“When Terminal 1 and 2 can’t depart passengers for an entire morning there is going to be an impact," he said.
“And I’m really sorry that happened and we’re now making sure as we look forward, that impact doesn’t carry on into tomorrow.”
Mr Woodroofe said an investigation into what happened is set to take place.
'Enormous queues'
Many England football supporters were hoping to start their journeys on Sunday to Cologne, where their team meets Slovenia in the Euro 2024 tournament on Tuesday.
Bobbi Hadgraft told BBC Radio Manchester she feared she would miss her flight when she arrived at the airport at 4am because of the “enormous queues”.
The power cut affected the airport and several surrounding buildings early on Sunday.
“Power has been restored and we are working to get those passengers already at the airport on to flights as soon as possible,” the airport added.
Passengers flying from Terminal 3 are advised to go to the airport as usual, although their flights could be subject to delays.
Passengers took to social media to complain about long queues for check-in desks at Manchester Airport, with images and videos showing people waiting in dimly-lit terminals.
The power cut came at the start of the busy summer season for Britain's airports.
Manchester is the UK's third busiest airport, handling about 27 million passengers a year travelling to 200 destinations.
It been a difficult few years for the UK's travelling public as both air and rail sectors have been periodically hit by a series of technical problems and industrial action.
A problem with immigration e-gates caused long delays for thousands of passengers last month, and last summer a technical issue with air traffic control caused widespread disruption.
