Russian troops have raped and tortured children in Ukraine, carried out a "large number" of executions and committed other war crimes, according to a United Nations investigation by legal experts.
Set up by the U.N. to probe the conduct of the war, the Independent International Commission of Inquiry reported its chilling findings Friday in Geneva, describing a long list of abuses and atrocities in four regions.
"Based on the evidence gathered by the commission, it has concluded that war crimes have been committed in Ukraine," Erik Mose, the chairman of the three-member commission, told the U.N. Human Rights Council.
Mose, a Norwegian judge, said the commission has documented cases in which children have been "raped, tortured and unlawfully confined."
"There are examples of cases where relatives were forced to witness the crimes," he added. "In the cases we have investigated, the age of victims of sexual and gendered-based violence ranged from 4 to 82 years."
Children also have been killed and wounded in "indiscriminate attacks" by Russian forces using explosive weapons, he said.
Mose said that he and his colleagues "were struck by the large number of executions in the areas that we visited."
The commission is investigating executions in 16 towns and settlements and has "credible allegations regarding many more cases of executions, which we are documenting further," he said.
The execution cases often featured "the prior detention of the victims as well as visible signs of executions on bodies, such as hands tied behind backs, gunshot wounds to the head, and slit throats," according to Mose.
For Ukrainians who were unlawfully detained, witnesses "provided us with consistent accounts of ill-treatment and torture," he said.
The update from the commission follows other allegations of war crimes from international human rights groups, Western governments and Ukrainian authorities, including the recent discovery of a mass burial site in the eastern town of Izyum.
The commission also had found two cases of "ill-treatment against Russian Federation soldiers by Ukrainian forces," he said. "While few in numbers, such cases continue to be the subject of our attention."
The commission focused on the regions of Kyiv, Chernihiv, Kharkiv and Sumy, visiting 27 towns and settlements and interviewing 150 victims and witnesses.
As it continues its investigation, it will examine the forced transfer of people and the alleged expedited adoption of children, Mose said.
The United States has accused Russia of interrogating, detaining and forcibly deporting hundreds of thousands of Ukrainians to Russia. An unknown number of children are believed to have been adopted by Russian families. The alleged deportations represent a war crime, violating the Geneva Conventions, U.S. officials say.
Russia has denied committing war crimes and defended its conduct of the war since it launched the invasion Feb. 24. Russian officials say Ukrainians who relocated to Russia traveled there voluntarily.
This article was originally published on NBCNews.com