Two unidentified drones crashed near Kouvola in southern Finland on Sunday, the defence ministry said, calling the incident a "suspected territorial violation".
"Drones have strayed into Finland's territory. We take this very seriously," Defence Minister Antti Hakkanen said in a statement, adding that security authorities had been sent to the scene.
Finland shares a 1,340-kilometre (830-mile) border with Russia.
Nearby countries Estonia, Latvia and Lithuania earlier this week said several Ukrainian drones had crashed on their territory after going astray during attacks on Russian oil export facilities on the Baltic Sea coast.
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'Low-flying slow objects'
"The investigation into the events is ongoing, and further details will be provided once the information has been verified," Hakkanen said.
According to the ministry, "a few low-flying slow objects were observed in Finnish airspace in the sea area and in southeastern Finland on Sunday morning".
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The air force sent up an F/A-18 Hornet fighter on an identification mission, it added.
"One drone has fallen to the ground north of Kouvola and another drone east of Kouvola. The police have cordoned off the areas for further investigation," the defence ministry said.
(FRANCE 24 with AFP and Reuters)