“This is an invisible emergency – a crisis most of the world has forgotten,” said UNICEF's Representative in Ukraine, Giovanna Barberis, in a news release.

“Children in eastern Ukraine have been living under the constant threat of unpredictable fighting and shelling for the past three years. Their schools have been destroyed, they have been forced from their homes and their access to basic commodities like heat and water has been cut off,” she stated.

The release attributed the increase – an additional 420,000 girls and boys – to the continued fighting and the steady deterioration of life in eastern Ukraine, where some 1.7 million people have been internally displaced, and many families have lost their incomes, social benefits and access to healthcare, while the price of living has sharply risen.

Hundreds of daily ceasefire violations put children's physical safety and psychological well-being at risk. The situation is particularly grave for the approximately 200,000 girls and boys living within 15 kilometres on each side of the 'contact line' in eastern Ukraine, a line which divides government and non-government controlled areas where fighting is most severe.

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In this zone, 19,000 children face constant danger from landmines and other unexploded ordinance and 12,000 children live in communities shelled at least once a month. Thousands of children are regularly forced to take refuge in improvised bomb shelters.

Teachers, psychologists and parents report signs of severe psychosocial distress among children including nightmares, aggression, social withdrawal and panic triggered by loud noises. More than 740 schools – one in five in eastern Ukraine - have been damaged or destroyed.

UNICEF once again calls for all sides to immediately recommit to the ceasefire signed in Minsk in August 2015 and to respect international humanitarian law, including allowing unrestricted humanitarian access.

UNICEF is appealing for $31.3 million to provide health and nutrition support, education, clean water, hygiene and sanitation as well as protection for children and families affected by the conflict. So far, about 10 per cent of the appeal has been funded.