Hundreds of schools in eastern Ukraine have been destroyed in fighting between Ukrainian government forces and Russian-backed rebels in the past two years, Human Rights Watch (HRW) said on Thursday.
Schools on both sides of the line of contact, which separates the combatants, have been hit and many, especially in rebel-controlled areas, are too damaged to reopen, HRW said.
Both sides have deployed forces in and near schools, turning them into military targets. Even schools that were not occupied have been attacked, the rights organisation said.
"Civilians, including children, on both sides of the line of contact have been bearing the brunt of this protracted war," said Yulia Gorbunova, Ukraine researcher at HRW.
"All parties to the conflict have a responsibility to protect children and to make sure that their hostilities don't cause further harm to their safety and education," Gorbunova added.
More than 9,000 soldiers and civilians have been killed since the conflict broke out in April 2014, when pro-Russian rebels rose up following Russia's seizure of Ukraine's Crimea region.
Fighting continues despite a year-old ceasefire agreement.
Last week the head of the Organisation for Security and Co-operation in Europe (OSCE), which monitors implementation of the ceasefire deal, voiced deep concern over escalating violence in eastern territories.
When military forces occupied schools, they often destroyed school furniture and equipment and left behind heavy artillery or unused munitions, HRW said.
In one case, HRW researchers found undetonated landmines on the school grounds, apparently thrown off a supply truck while it was parked in the schoolyard.
Progress has been made in repairing and reopening damaged schools, particularly in government-controlled areas of Luhansk and Donetsk regions, thanks in large part to leadership by parents and teachers, HRW said.
But local authorities and school administrators in many places told researchers the risk of renewed fighting made them reluctant to fund or carry out school renovations.
Ukrainian authorities do not recognize school documents issued in rebel-held areas of Donetsk and Luhansk regions, so some parents in rebel-held areas send their children to schools in areas under government control, HRW said.
The journey across the line of control is slow because of travel restrictions imposed by the Ukrainian government, and can be dangerous, due to sporadic shelling and the presence of mines, HRW said.
"Teachers and parents on both sides of the contact line have shown tremendous commitment to continue children's education despite the war," Gorbunova said.
"The warring parties should also do a lot more to avoid irreparably harming children's safety and education," she added.
The researchers visited 41 schools and kindergartens between September and November 2015, in both government-controlled areas and territory controlled by Russian-backed rebels.