After appropriate checks on Sunday night, police found no threats on the aircraft, flying 160 passengers, a security spokesman in Berlin said.
The travelers resumed their journey to the Polish city on another aircraft, the source added, cited by the news without giving details about the alert.
The aircraft requested an emergency landing and was immediately cleared, Berlin-Brandenburg airport spokesman Jan-Peter Hack told the Bild daily.
This is the second incident in a week involving aircrafts from the Irish airline after another plane flying to Vilnius (Lithuania) had to make an emergency landing in Minsk on May 23 due to another false bomb threat.
As a result of the landing, the Belarusian authorities arrested journalist Roman Protasevich and his Russian girlfriend. The man is considered one of the instigators of violent protests in that country after the August 2020 election in which Aleksandr Lukashenko was re-elected.
Another Ryanair plane, on the Dublin-Krakow route, landed in London in July, 2020, because of another false bomb threat.