Finnish army clears hundreds of wartime explosives annually

Finnish defence forces remove between 300 and 400 wartime explosives from the ground each year, the army’s land forces command told public broadcaster Yle on Saturday.

The discovery of a Soviet-era incendiary bomb in Riihimäki last month was not unusual, as unexploded ordnance from the Second World War continues to surface regularly across Finland. Authorities warn that even decades-old explosives remain dangerous and must not be handled.

Most finds occur in former battle zones, bombed cities, or even private properties, where soldiers may have brought back live ammunition as war souvenirs. In northern Finland, German explosives are occasionally uncovered in areas where retreating forces destroyed their own materiel.

The army also conducts proactive sweeps in suspected areas. The latest case—a Soviet ZAB-2.5 incendiary bomb found in a Riihimäki field in May—was left unguarded for nearly 24 hours before police secured it. Had it detonated, the blast radius could have reached 10 metres, according to police estimates.

Unexploded ordnance ranges from small “bear” mines containing just grams of explosives to massive 250-kilogram aerial bombs, like one discovered in Rauma in October 2025. Authorities stress that all finds must be reported to police immediately, as age does not reduce the risk of detonation.