New survey data shows that children in Ukraine are experiencing a “widespread learning loss” during Russia’s invasion, Unicef, the UN children’s agency, said on Tuesday.

The educational problems underscore the widespread social damage to Ukraine caused by Russia’s full-scale invasion 18 months ago, adding to the emotional and mental toll on young Ukrainians. Over the course of the war, some schools were bombed and others were converted into shelters.

The UN human rights monitoring mission in Ukraine said in June that more than 530 children had been killed and 1,047 wounded since the conflict began, figures that are likely to be an undercount. Russia and its proxy forces in Ukraine have also moved some children to camps in Russian-occupied areas or to Russia itself, sometimes for adoption.

The long period of turmoil has left teachers and school administrators struggling to figure out how to provide classes for the millions of children that remain in Ukraine, many of them displaced from their homes, and for those who have left the country, a number that some estimates put at around two million.

Up to 57 per cent of Ukrainian teachers have reported a deterioration in their students’ language abilities, as well as lower math and foreign language skills, Unicef said.

Regina De Dominicis, the agency’s regional director for Europe and Central Asia, said that “inside Ukraine, attacks on schools have continued unabated, leaving children deeply distressed and without safe spaces to learn”.

“Not only has this left Ukraine’s children struggling to progress in their education,” she said, “but they are also struggling to retain what they learned when their schools were fully functioning.”

The most recent enrollment data for Ukrainian schools found that about a third of primary- and secondary-age children were learning in person, while another third were taking a mix of in-person and online classes.