Before Russia invaded Ukraine, Varvara Tupkalenko's two sons played at home with miniature cars, like many boys their age.

Today, plastic guns are the favored toys in their living room in the village of Kalynove, just 15 kilometers from the Russian border in the northeastern Kharkiv region.

Instead of scampering across playgrounds, Andrii, 8, and Maksym, 6, climb through abandoned trenches and charred shells of armored vehicles that sit on the outskirts of the village.