The bell rings for the end of lessons at Bakhmut’s School Number 18 in the Donetsk region of eastern Ukraine, and children come pouring out of the building.

Historically, Russian has been the dominant language here. It is a short drive to the frontline of the country’s three-year-old war with Russian-backed separatists, who briefly overran the city early in the conflict. But as the children make their way home, some are speaking Ukrainian — a sign of a growing drive to make it the main language here.

Russia once used language to divide Ukrainians — justifying its annexation of Crimea in 2014 and its backing for separatists on the grounds that it was protecting Russian-speakers. As Ukraine has pushed back with efforts to promote its national identity, language has become the battleground once more, with education the new frontline. But that risks making Russian complaints about language discrimination — overhyped in the past — come true now. “My daughter cries at night because she can’t understand the homework.”

“My daughter cries at night because she can’t understand the homework,” said Olga Sergienko, who says she was told just before starting at School 18 that her seven-year-old would not be taught in Russian. Like other parents with children there, she feels her rights have been violated — but it was too late to find another school, and in any case the alternatives are running out.