KYIV, Ukraine >> Competing claims emerged over a deadly attack on a boarding school in Sudzha, a city in Russia’s Kursk region that has been under Ukrainian control for five months, with Ukraine and Russia accusing each other of carrying out the strike.

The General Staff of Ukraine’s Armed Forces said Saturday night that four people were killed and a further four seriously wounded in the strike, with 84 people rescued by Ukrainian servicemen from the rubble of the building. Ukrainian President Volodymyr Zelenskyy said that Moscow had bombed the boarding school where civilians were sheltering and preparing to evacuate.The General Staff said those in need of additional medical assistance were evacuated to medical facilities in Ukraine.

The Russian Ministry of Defense claimed in the early hours of Sunday that it was Ukrainian forces that had launched a missile strike on the school, saying that the missiles were launched from Ukraine’s Sumy region.

Neither side’s claims could be independently verified.

Ukrainian officials said that some 90 Russian civilians displaced by the nearby fighting had been sheltering in the school when the attack occurred. Oleksiy Dmytrashkivkyi, a military spokesperson in the area, said in text messages that four of those people had been killed and 10 injured.

“They destroyed the building even though dozens of civilians were there,” Zelenskyy said Saturday night in a social media post, emphasizing that those were Russia’s “own civilians.” He shared images of the ruins and of people covered in dust, visibly shaken by the attack.

Sudzha, a small town near the Ukrainian border in Russia’s western Kursk region, was captured by Kyiv’s forces during a cross-border assault last summer and has since been occupied by Ukraine.

Meanwhile, the death toll from a Russian missile strike on an apartment block in the Ukrainian city of Poltava on Saturday rose to 14, including two children, local officials said Sunday. Seventeen people were injured in the attack on the five-story building, Ukraine’s State Emergency Service said.

Saturday’s attacks — striking cities both near and far from the front lines and killing people from both warring nations — underscored the brutal toll of the war on civilians. Since Russia’s invasion began nearly three years ago, more than 12,300 civilians have been killed, a U.N. official reported just before Christmas.

The United Nations noted a sharp increase in casualties last year because of the use of long-range drones, missiles and glide bombs capable of reaching distant targets. Cities once considered relatively safe — like Lviv, in western Ukraine, and Poltava — now face frequent attacks. In Kyiv, the once-rare buzz of Russian drones flying overhead now echoes regularly through the night.

Denys Kliap, the director of Free and Unbreakable, a volunteer emergency response team in Poltava, said he and his colleagues rushed to the site of the attack as soon as they heard explosions, finding a pile of rubble and a residential building on fire. “I heard incredible screams from people,” he recalled. “People were moaning from under the rubble, shouting for help.”

As he moved closer to the building’s remains, Kliap, 26, came across the torn body of a woman in the rubble. Inside, a colleague found another woman with an open wound, bleeding heavily. Other residents were in a state of shock, he said.

Photographs from the emergency services showed that several floors of the building had collapsed. Some apartment rooms were left miraculously intact, their doors opening onto the void left by a neighboring collapsed apartment. Clothes dangled into the emptiness, suspended on steel bars and cables.

On Sunday morning, Ukrainian emergency services were still searching through the rubble left by the missile strike the day before. They said they had rescued 22 people. Kliap, speaking by phone from the site, said relatives of residents had gathered there, hoping for survivors.

“But the rescuers often only find dead bodies,” he said.

The strike in Poltava rekindled memories of a previous attack, in September, on a military academy that killed 50 people, many of them students. Russian missiles had hit the academy only minutes after air-raid alarms blared. “For the last year, the feeling of danger among citizens of Poltava has increased,” Kliap said.

Moscow sent 55 drones into Ukraine overnight into Sunday, Ukrainian officials said. According to Ukraine’s Air Force, 40 drones were destroyed during the overnight attacks. A further 13 drones were “lost”, likely having been electronically jammed.

Two people were wounded in a drone attack in the early hours of Sunday morning in the Kharkiv region, according to regional Gov. Oleh Syniehubov.

Later on Sunday, five people were wounded when a Russian drone hit a bus in the city of Kherson on Sunday, local Gov. Oleksandr Prokudin said.

In Russia, the Defense Ministry said that five Ukrainian drones were shot down overnight in five regions of western Russia: three over the Kursk region, and one each over the Belgorod and Bryansk regions.

A man was killed in a drone strike in the Belgorod region, regional Gov. Vyacheslav Gladkov said.