This week, on 10 June, the Finnish Border Guard spotted four Russian military aircraft violating the country's airspace, Yle reports.
At the same time, the weather conditions were good, so they could not affect the choice of route.
Border guards say that the Russian aircraft - two bombers and two fighters - flew no more than 2.5 km over Finnish territory.
At first, the Finnish side claimed one aircraft. Now it says there were four.
The last time a similar incident was reported was in August 2022. Back then, two Russian fighter jets entered Finnish airspace in the Gulf of Finland.