The death toll from a Russian rocket attack launched as Ukraine observed its Independence Day has risen to 25, a Ukrainian official said Thursday. The victims included an 11-year-old boy found under the rubble of a house and a 6-year-old killed in a car fire near a train station that took a hit, the deputy head of the Ukrainian presidential office, Kyrylo Tymoshenko, said. A total of 31 people sustained injuries, he said.

The strike served as a brutally painful reminder that Russia is capable of employing military force in ways that maximize civilian suffering, testing Ukraine’s resilience after six months of a grinding war.

In Geneva on Thursday, the UN’s human rights chief, Michelle Bachelet, decried the time since President Putin sent troops into the neighboring country as “unimaginably horrifying.” She called on Mr. Putin “to halt armed attacks against Ukraine.”

The lethal train station strike took place at Chaplyne, a town of about 3,500 people in the central Dnipropetrovsk region. It came after President Zelensky warned that Moscow might attempt “something particularly cruel” this week as Ukraine marked both its 1991 declaration of independence from the Soviet Union and the six-month point of Russia’s invasion on Wednesday.

“Chaplyne is our pain today,” Mr. Zelensky said during his evening address, indicating that retribution for Russia would not be long in coming. “We will definitely make the occupiers bear responsibility for everything they have done,” he said. “And we will certainly drive the invaders out of our land.”

Hours before the train station attack, Russia insisted it was doing its best to spare civilians, even at a cost of slowing down its offensive in Ukraine.

The Russian defense minister, Sergei Shoigu, speaking Wednesday at a meeting of his counterparts from a security organization dominated by Russia and China, said Russia was carrying out strikes with precision weapons against Ukrainian military targets, and “everything is done to avoid civilian casualties.”

“Undoubtedly, it slows down the pace of the offensive, but we do it deliberately,” he said.

It was the second time Mr. Shoigu has made such a claim; he said the same thing in late May.

Elsewhere in Ukraine, three people were killed in the eastern region of Donetsk on Wednesday and one more was wounded, Governor Pavlo Kyrylenko said on Telegram.

Nikopol, a city across the river from the Zaporizhzhia Nuclear Power Plant, came under more Russian shelling overnight, the governor of the Dnipropetrovsk region, Valentyn Reznichenko, said.

A cycle of attacks and counter-attacks has turned the half-year-old war into what the Washington Post called “a costly, grinding affair full of momentum swings.”

On August 22, the commander-in-chief of Ukraine’s armed forces, Valery Zaluzhny, stated that 9,000 Ukrainian soldiers had been killed since the war began. 

In an article about the rising number of wounded soldiers, the French newspaper Le Monde interviewed the director of a rehabilitation center outside Kyiv, Andriy Ovcharenko, who said that authorities do not release figures on amputees “so as not to demoralize Ukrainians.” Underlining the cruelty of the war in all its aspects, Mr. Ovcharenko added that “if people knew how many people are losing their arms and legs, no one would join the army.”

Ukraine’s losses, awful as they are, still pale compared to those of Russia. Ukraine’s military general staff reported today that Russia has lost 45,850 troops since the country invaded Ukraine on February 24.