Ukrainian forces are violating international law and endangering civilians by establishing bases in residential areas, including in schools and hospitals, Amnesty International said on Thursday, drawing a furious response from Kyiv.
Kyiv said the rights group was drawing a "false equivalency" between the actions of Russia's invading forces and Ukrainians defending their homeland.
Amnesty had tried to "amnesty the terrorist state and shift the responsibility from the aggressor to the victim", Ukrainian President Volodymyr Zelenskyy said later on Thursday in his daily address.
"There is no condition, even hypothetically, under which any Russian strike on Ukraine becomes justified. Aggression against our state is unprovoked, invasive and terrorist.
"If someone makes a report in which the victim and the aggressor are supposedly equal in some way, if some data about the victim is analysed, and the aggressor's actions at the same time are ignored, then this cannot be tolerated," he added.
Amnesty said in its report the tactics "in no way justify Russia's indiscriminate attacks", and some Russian "war crimes" including in the city of Kharkiv were not linked.
But it listed incidents when Ukrainian forces appeared to have exposed civilians to danger in 19 towns and villages in the Kharkiv, Donbas and Mykolaiv regions.
"We have documented a pattern of Ukrainian forces putting civilians at risk and violating the laws of war when they operate in populated areas," Amnesty secretary-general Agnes Callamard said.
"Being in a defensive position does not exempt the Ukrainian military from respecting international humanitarian law."
Residential areas where Ukrainian soldiers based themselves were miles away from frontlines, and "viable alternatives" were available that would not endanger civilians, the report said.
But it said the soldiers had failed to tell civilians to evacuate the areas, despite launching strikes on Russian forces that exposed them to retaliatory fire.
Amnesty researchers witnessed Ukrainian forces using hospitals as "de facto military bases" in five locations, and in 22 schools.
Although the schools have been shut during the conflict, they were located in civilian neighbourhoods.
"We have no say in what the military does, but we pay the price," the report quoted one resident as saying.
Ukraine's government pushed back hard at the report, with Foreign Minister Dmytro Kuleba branding the allegations "unfair".
"This behaviour of Amnesty International is not about finding and reporting the truth to the world, it is about creating a false equivalence -- between the offender and the victim, between the country that destroys hundreds and thousands of civilians, cities, territories, and a country that is desperately defending itself," he said.
Defence Minister Oleksiy Reznikov called the report a "perversion" as he said it questioned the right of Ukrainians to defend their country.
Top presidential aide Mykhailo Podolyak insisted Ukraine's armed forces take all measures to move civilians to safer areas and suggested Amnesty was complicit in spreading Kremlin disinformation.
"The only thing that poses a threat to Ukrainians is (a Russian) army of executioners and rapists coming to (Ukraine) to commit genocide," he tweeted.