The flight from Berlin to Athens issued a distress signal and sought permission to make an emergency landing while flying over the Halkidiki region of Greece, the civil protection ministry said.
The ministry said the crew had reported a fire, but a Ryanair spokeswoman said the emergency had been triggered by an “unidentified odour in the cockpit and cabin” and that there had been no fire.
Emergency protocols were deployed and the aircraft landed safely at Thessaloniki’s Macedonia airport, where 157 passengers, an infant and six members of the crew disembarked.
In a statement, Ryanair apologised to passengers, and noted that they boarded a replacement aircraft to Athens within two hours.