Before Russia invaded Ukraine, Varvara Tupkalenko’s two sons played with miniature cars like typical boys. Now, plastic guns dominate their living room in Kalynove, a village 15km (9 miles) from the Russian border in northeastern Ukraine’s Kharkiv region.

Andrii, eight, and Maksym, six, once enjoyed playground games, but they now explore abandoned trenches and burned-out armoured vehicles on the village’s outskirts.

“They’re kids afflicted by war,” Tupkalenko said.

Europe’s largest land conflict since World War II is transforming devastated Ukrainian frontier communities like Kalynove, inflicting both visible and invisible wounds on their youngest residents.

These hidden traumas extend beyond anxiety and fear to more profound effects, including poverty, depression and stunted emotional development, according to a February report by the NGO Save the Children.

“This is how a lost generation becomes a reality,” the report said. “The longer the conflict continues, the more likely it is that these children will grow up without the opportunities and resources necessary to recover and normalise their lives.”

When the Reuters news agency first visited Kalynove in late March, the boys were among six children remaining in the shrapnel-scarred village, whose landscape of open fields and gentle hills bears witness to Russia’s February 2022 invasion. Now they are the last children remaining after the others fled with their families, their mother said.

Although a Ukrainian counteroffensive in late 2022 pushed Russian forces back from the village perimeter, both armies continue exchanging fire just 20km (12 miles) away, leaving the Tupkalenkos struggling to preserve any semblance of normal childhood.

Military games dominate the boys’ play, including setting up pretend checkpoints to inspect fellow villagers. Their wooden fort features cloth netting – protection, they explain, from drones.

According to the Office of the United Nations High Commissioner for Human Rights, at least 30 children have been killed and 120 wounded by landmines or unexploded ordnance in Ukraine since Russia’s invasion.