Russia launched a pre-dawn missile barrage on Ukraine’s capital Thursday, killing 3 people including a 9-year-old and her mother, officials said, and damaging apartment buildings, schools and a children’s hospital. It was the highest casualty toll from a single attack on Kyiv over the past month.

A 33-year-old woman died as she and others waited to enter a locked Kyiv air raid shelter, leaving her and others at the mercy of falling missile fragments, according to her husband. Officials ordered an investigation into what happened.

The latest Russian attack, using what Ukrainian officials said were short-range Iskander ground-launched missiles, coincided with events scheduled in Kyiv to celebrate International Children’s Day. Those events were canceled.

Ukrainian air defenses shot down all 10 cruise and ballistic missiles launched by the Kremlin’s forces, but falling debris caused damage and casualties on the ground, wounding 16 people, according to authorities.

Russia has kept up a steady barrage on the Ukrainian capital and other parts of the country in recent weeks as Kyiv readies what it says is a counteroffensive to push back Moscow’s troops, 15 months after their full-scale invasion. Kyiv was the target of drone and missile attacks on 17 days last month.

Ukraine’s first lady, Olena Zelenska, said one child was in hospital after the attack.

“Children’s Day has to be about safe childhood, summer, life,” she tweeted. “But today it is about new crimes of (Russia) against children.”

Mother and Child Killed in Kiev Bombardment

Ukrainian Foreign Minister Dmytro Kuleba tweeted that the dead included a 9-year-old girl, her mother and another woman.

At the Kyiv air raid shelter that was locked, Yaroslav Riabchuk said he and his wife of 17 years, Natalia, were outside with others when he ran around the back of the building to summon the guard in charge.

“I ran, but then an explosion happened,” Riabchuk said. “Shattered glass started falling, and I knew I had to run back. When I returned, it was over. There was a lot of blood, women, children.”

Mayor Vitali Klitschko said authorities were investigating what happened. He gave orders to the heads of the city’s districts to immediately check if all the shelters in Kyiv are accessible.

U.N. human rights monitors said six children were killed and 34 were wounded last month alone.

Since February 2022, at least 525 children have been killed and at least 1,047 have been injured, according to the U.N.’s Human Rights Monitoring Mission in Ukraine.

“Sadly, as the world marks International Children’s Day, there is little to celebrate in Ukraine where civilians, including children, continue to pay a heavy price” said Matilda Bogner, the mission’s chief.

In Moscow, meanwhile, Russian President Vladimir Putin was chairing a meeting with families via video link to mark International Children’s Day.

Putin met with families that have many children and vowed to maintain state subsidies and other measures to support them. When one of the participants in the meeting voiced confidence that Russia would be victorious in what the Kremlin calls the “special military operation” in Ukraine, Putin noted that “it will be so.”

“There is no doubt about it, because we are protecting our land, our people and our values,” he said.

The Ukrainian Ministry of Defense cited different figures for child casualties in the war, saying at least 484 children have been killed and 992 injured. It was not immediately possible to reconcile the differences with the U.N. figures.

Russia has repeatedly targeted Kyiv with waves of drone and missile attacks since the start of the invasion, but attacks against the capital have significantly intensified over the past month. While Ukraine’s air defense has become increasingly effective at intercepting Russian drones and missiles, many Kyiv residents are anxious and tired after weeks of sleepless nights.

Thursday’s onslaught also damaged apartment buildings, a medical clinic, a water pipeline and cars. Earlier, the city government had said that two children were killed before revising the number to one.

One explosion sent missile fragments ripping through an apartment building in a leafy neighborhood. In the morning light, paramedics escorted an elderly woman gingerly away from the building as the bare feet of a person killed in the attack poked out from underneath a plastic tarpaulin in a roped-off area between the trees.

“Around 3 a.m. there was a strike over there. I woke up and saw the fire. My door was smashed, I woke up my mom and ran to the corridor,” said resident Nikita Maslun, peering through a broken window. “Then we went down and ran outside. We saw people running. Windows were shattered and balconies destroyed.”

In Desnianskyi district, debris fell on a children’s hospital and a nearby multistory building. Two schools and a police department were damaged. In other areas, blast waves blew out windows.

After a woman was killed watching an aerial attack from her balcony earlier this week, Kyiv authorities urged residents to heed warning sirens and stay in shelters or other safe locations. “You’ve got to be vigilant, as ballistic missiles fly at incredible speeds. From the moment the alarm is announced to the rocket’s arrival, you have only a few seconds!” they warned in a message to residents.

Across Ukraine, the presidential office said Thursday, a total of seven civilians were killed and 27 injured over the previous 24 hours.

Elsewhere, a group that calls itself the Russian Volunteer Corps, and purports to include Russians fighting on the Ukrainian side, released a video claiming that they were on the border with Russia and about to launch a cross-border raid on the town of Shebekino in the Belgorod region.

A similar group that calls itself the Freedom of Russia Legion also announced a plan to launch a cross-border raid.

Belgorod Gov. Vyacheslav Gladkov said that Ukrainian shelling left eight people wounded overnight but there had been no incursion by enemy forces.

Some Russian media outlets said that Ukrainian forces made an attempt to cross the border but were repelled by Russian troops.

The two groups claimed responsibility for a cross-border raid last month that marked one of the most serious such attacks on the Russian territory ,engaging in fighting with Russian forces that prompted authorities to evacuate residents of a town near the border.

Some observers saw the raids as part of Ukrainian efforts to probe Russian defenses and distract Moscow’s military resources ahead of a planned Ukrainian counteroffensive.