The drone appeared similar to the ones that fell inside the country in late March, which Kyiv said were knocked off course by Russian interference.

A crashed "unmanned aircraft" had been found in a forest in Iitti in southern Finland, police told AFP.

"According to current information, the drone found in the forest is similar to those previously found in southeastern Finland," police said in a statement.

An "unexploded warhead" had been found inside the cordoned off area, which the military is due to disable, police said.

No details were provided on the origin of the drone or when it crashed.

According to current information, the aircraft -- which was found around a kilometre from the closest residential area -- had not caused any injuries or property damage, police said.

On 29 March, two stray drones crashed in Finland and two days later a third fallen drone was detected.

Two of the fallen unmanned aircraft were confirmed as Ukrainian.

Ukraine has apologised to Finland, explaining that the drones were likely knocked off course by Russian interference.

Kyiv has in recent weeks struck port facilities on the Russian coast in the Gulf of Finland, close to Russia's border with the NATO and EU member.