A domestic Finnair flight headed from Helsinki to Joensuu on Friday morning was unable to land due to GPS interference, according to the flag carrier.
The aircraft circled above the eastern city of Joensuu for some time before returning to Helsinki Airport, according to data from the global flight tracking website Flightradar24.
Friday's return flight from Joensuu to Helsinki was also cancelled.
Finnair's communications team told news service STT that the 21 passengers on board the diverted flight had been rebooked on an afternoon departure, which is expected to operate as planned.
A similar incident in June saw another Joensuu-bound flight from Helsinki unable to land in the eastern city due to GPS issues, leading to disruptions in flights between the cities.
There were also reports in early June of farm tractors near the eastern border receiving inaccurate GPS positions due to suspected Russian interference.
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