More than 30 Ryanair passengers, some bleeding from their ears, have received hospital treatment in Germany after their plane to Croatia lost cabin pressure, German police say.
Flight FR7312 from Dublin to Zadar made an emergency landing in Frankfurt.
The airline said oxygen masks were deployed and the crew carried out a "controlled descent".
The plane descended 8,000m (26,000ft) from 11,300m to 3,000m in seven minutes, according to Flight Radar.
Passenger Miomir Todorovic tweeted a photo of the interior of the cabin as the plane lost altitude.
Ryanair said the plane "landed normally and customers disembarked, where a small number received medical attention as a precaution".
The plane was carrying 189 passengers, 33 of whom were hospitalised, and some decided not to continue with their journey, German police said.
'People are screaming'
"We get on the plane, we're flying and next of all the oxygen mask comes down, we're left in darkness for 15 minutes, there's no reassurance just people shouting 'emergency, emergency'," Sarah McGarry told the newspaper.
"There was a newborn baby and children on the flight, people are screaming and we don't know what's going on for 15 minutes . . . Then finally we're told that we're going to Germany."
Another passenger told the newspaper: "It was really scary, there were three to four minutes (that felt like an hour) when the plane was falling fast and I thought we were done for".
'Abandoned in the airport'
Passengers also criticised their treatment once they had landed, saying they had not been given enough food and drink and had been forced to sleep on a concrete basement floor or on camp beds.
Spanish passenger Minerva Galvan said on social media that those on board had been "abandoned" at Frankfurt Hahn airport after going through a "very scaring moment".
Nightmare Ryanair flight FR7312 on way to Croatia. Emergency landing at Frankfurt. Overnight in military base camp beds- good old Ryanair style customer service. Cutting costs and more profit for Ryanair all at the expense of customer safety. Shame on you Michael O Leary— Paul Wiseman (@WisemanPaulk) July 14, 2018
100 Mcdonald cheese burgers arrived at 5 in morning for a plane with 189 passengers. Thank you Ryanair. No wonder your people are striking.— barry holden (@barelyholdenon) July 14, 2018
Ms McGarry, who was with three children, said her eardrum burst during the descent but said she did not go to hospital because she was not told whether she would get back to the airport in time to catch the rescheduled flight.
In its statement Ryanair said it would pay for hotels for the affected passengers but added that there was a "shortage of available accommodation".
Earlier this week a co-pilot smoking an e-cigarette on an Air China flight caused the plane to start a rapid emergency descent, bringing the plane 6,500m lower, investigators said.
The co-pilot tried to conceal his actions but accidentally shut off the air-conditioning, causing oxygen levels to fall.
Ryanair is Europe's largest airline by passenger numbers, according to the International Air Transport Association. It flies in 37 countries and carried 130 million passengers last year.