Svitlana tears up thinking of the bombing that leveled her son Illia's school in Lysychansk, a city in the eastern Ukrainian region of Luhansk now occupied by Russian forces, but she is determined to ensure the eighth-grader continues his studies.

"My son's school is not there anymore. It was bombed completely - and it can never be restored," she said, during a visit to Illia's new school in Irpin, near Kyiv, where workers are replacing windows blown out during a Russian artillery attack before school starts on Sept. 1.

"I think we will have a better life here," said Svitlana, who asked that her surname not be used. "The most important thing is for our children to learn."

Across Ukraine, authorities are building bomb shelters and repairing thousands of buildings damaged in shelling by Russian forces before the country's nearly 6 million school-aged children return to school in September - online or in person.

Resuming school is a top priority for the government given the war's long-term social and economic impact on the country, its children and the willingness of those who fled to return.

"The Russian aggression will have huge consequences for the Ukrainian educational system," said Ivan Prymachenko, co-founder of Prometheus, the largest Ukrainian online learning platform.

Nearly 2,300 educational institutions were shelled or bombed since the Russian invasion began on Feb. 24, and 286 were completely destroyed, according to Ukraine's Ministry of Education and Science. More than 350 children have died and 586 were wounded during what Russia calls a "special military operation," U.N. data show. The total could be much higher.

Officials are keen to resume education, in part to enable women to return to work. But assessing about 80% of Ukraine's 26,000 educational facilities, from preschools to universities, the interior ministry found only 41% have the bomb shelters or protective structures needed for in-person instruction.

That's a 400% rise from a few months ago and more shelters could still be completed in the next weeks. But availability is low near the front: In the Mykolaiv region where Russian forces recently stepped up shelling, only 16% of schools have shelters in place.

As a result, millions of children and youth will be forced to continue learning remotely, compounding problems already evident after two years of COVID-19 related closures, including high dropout rates among teenagers, said Sonia Khush, Ukraine country director for Save the Children.

NO 'WIN-WIN'

"There is no win-win in this situation," says Oleksii Riabchyn, ex-deputy energy minister and adviser to the CEO of state-energy company Naftogaz.

Riabchyn fled to Lviv in western Ukraine with his family on the day of the invasion, but has since come back to Kyiv with his wife. They are now agonizing over whether to bring their children back to Kyiv, where they would have to run 15 minutes to the subway station in the event of an attack.

Riabchyn hopes to at least bring his six-year-old son to Kyiv for traditional celebrations ahead of starting first grade.

"We face a matrix of options - and all of them are bad. This is the compromise," he said.

Learning interruptions have long-term consequences, including lower income later in life. The World Bank in February estimated that globally a 7-month absence from schools due to COVID-related closures would increase the share of students in "learning poverty" to around 70% unless swift action was taken.

In Ukraine, war exacerbates these problems.

"If kids don't get educated ... that is going to have a permanent lasting legacy, and the recovery will be longer, harder and more expensive," said Arup Banerji, World Bank regional country director for eastern Europe.

Ukraine has excellent internet access, but educational authorities - especially in frontline areas - are asking for more laptops and other devices, Khush said.

Even if schools open in person, pupils will need additional support to adjust while some may have to adopt split shifts.

The Irpin school's bomb shelter can house 300 children, a fraction of its 2,000 pupils, school director Ivan Ptashnyk told Reuters.

Learning gaps caused by the war are a "tragedy for Ukraine," said Volodymyr Melnyk, president of Lviv National University. The university is creating programs to help teachers work better online while thousands of students volunteer to help refugees.

Former Ukrainian finance minister Natalie Jaresko said restoring education will encourage the return of millions of women and children who fled to Europe after the war began.

"That's the future labour force - it's the future of the nation, in effect," Jaresko told Reuters.

TRAUMA

Addressing war trauma will also be a big challenge.

Clinical pyschologist Olena Romanova works with displaced children and adults in Lviv, using colorful, stuffed animals to help children work through memories of death and destruction.

"Whatever is going on, we need to laugh," said Romanova. "A lot of (their) memories would be about this awful war ... (but) we try to make their life more positive."

Ukrainian non-governmental organization BASE UA uses arts including theater to help displaced teens process war memories.

Vika Okhrymenko, 14, who fled from Russian-occupied Oleshky, said the group's summer camp in the Carpathian Mountains offered her respite from the realities of conflict, but she misses her home.

"I feel like I've lost a big part of communication with my classmates," she said. "I'd like to come back and see them in school, learn, and for everything to go back to normal."