Credit…Efrem Lukatsky/Associated Press

At least 437 children are among more than 8,300 civilians who have been killed in Ukraine since Russia launched its full-scale invasion in February, the country’s prosecutor general said on Saturday in a grim new accounting of the war’s toll.

Andriy Kostin, Ukraine’s prosecutor general, said that in addition to the death toll, more than 11,000 civilians had been injured in the conflict. He said that the actual numbers could be much higher because authorities in Kyiv don’t have access to data from the areas to the east and south that Russian forces have occupied.

On Nov. 14, the Office of the U.N. Human Rights reported that 408 children were among the 657 people who were killed in the invasion. 750 other were among the 10,074 injured. But it did not say what the true figures were. “certainly higher.” It is data showed that March had been the conflict’s deadliest month.

The majority of civilian casualties have been caused by Russian missiles being fired from artillery positions near front lines or at greater distances towards towns and cities. Children were also among the victims of some of the conflict’s worst massacres of civilians, including a missile strike on a railway platform in the city of Kramatorsk in Donetsk region in April, which killed more than 50 people, and an attack on a civilian convoy in Zaporizhzhia region in September when at least 30 people died. Both civilians fled the fighting in both instances.

In one of the war’s most poignant casualties, a 4-year-old girl with Down syndrome, Liza Dmytriyeva, died of shrapnel wounds in July after a shopping mall was struck by a missile in the city of Vinnytsia in central Ukraine. Pictures of the pink-and-black stroller that she left on the street were shared around the globe.

Ukraine’s government has made a strenuous effort to document crimes committed since the Russian invasion began, with a view to mounting prosecutions. According to Mr. Kostin’s statement, Ukrainian authorities have recorded 45,000 war crime records.

He stated that 216 people had been notified of their suspicions of involvement in war crime, 17 of which were Russian prisoners.

The United Nations appointed a panel to review legal issues and concluded that Russian soldiers committed war crimes against Ukraine. Children were also raped, tortured and beaten.

In addition to missile strikes, Ukrainian authorities have uncovered a succession of atrocities in areas — such as Bucha, a suburb north of the capital, Kyiv; Izium in the Kharkiv region; and, most recently. the city of Kherson — from which Russian forces have been forced to retreat. Some victims were children.

The authorities have uncovered detention centers in Kherson for teenagers and said that young people appeared to have been tortured, according to the Ukrainian Parliament’s commissioner for human rights, Dmytro Lubinets.

“There was a separate area where teenagers were detained. We are now determining their ages. People are testifying that some boys looked 14 years old,” According to Mr. Lubinets, the practice was first reported by authorities in a Facebook post.

Russian rockets and bombs have caused damage to thousands of schools, with many being destroyed. In an example of the misuse of children’s facilities, Oleh Synehubov, head of the regional administration in Kharkiv, said on Telegram on Friday that Russian forces had planted mines in beds in kindergartens in the region. This claim was not independently verified.