At least 37 people were killed when an overnight Russian drone strike on a depot near Kyiv sparked a huge fire and explosions, authorities said Saturday.
The depot, near the capital's western suburbs, appeared to have been storing "explosive objects", Ukrainian prosecutors said, as President Volodymyr Zelensky suggested ammunition was to blame.
"Those who allowed this to happen must be held accountable for their decisions... ammunition cannot be stored near homes or other residential areas," he wrote on X.
Both Russia and Ukraine have intensified long-range strikes on each other in recent months, sparking fires and pushing civilian casualties to their highest level since Moscow invaded in 2022.
AFP reporters saw a huge column of black smoke rising over the capital's western suburbs, as officials reported that hundreds had been evacuated from the area.
The blast damaged surrounding residential areas, as well as a care home for the elderly and disabled people, Zelensky said.
At least 37 people were killed, among them the mayor of the nearby town of Dmytrivka, Kyiv region governor Tymur Tkachenko said on Telegram.
"Rescuers and all relevant services are continuing their operations at the scene of the tragedy," he said.
The depot was located in the town of Myla, on Kyiv's western outskirts.
Officials did not say whether it was a military or civilian facility.
Ukrainian prosecutors said they had opened an investigation.
"On 28 August at around 8:10 pm (1710 GMT), an unmanned aerial vehicle... fell on or struck the grounds of an enterprise in the town of Myla," the office of Ukraine's prosecutor general said.
"A large-scale fire broke out on the enterprise's grounds, and detonation began," it added.
The prosecutor's office said that its investigation would focus on "the legality of the... storage of explosive objects and materials on the enterprise's grounds", as well as whether the owner, whom it did not name, had the "necessary permits and approvals".
Ukrainian Prime Minister Sergiy Koretsky expressed regret that a "lesson" had not been learned following a previous deadly strike on a munitions depot near Kyiv in July.
That investigation revealed serious failings on the part of a state-owned company, which did not comply with regulations regarding the proximity of residential buildings.
"In the fifth year of the full-scale invasion, making the same mistakes over and over is criminal negligence," he said on Telegram.
"Everyone responsible, without exception, must face severe punishment so that such situations never happen again."
Russia launched at least two missiles and 267 drones at Ukraine between late Friday and early Saturday, according to the Ukrainian air force.
In addition to the depot strike, Russian attacks on Ukraine killed three people on Saturday, including a two-year-old infant in Kyiv and a 14-year-old girl in the capital's outer suburbs, officials said.
In Russia, Ukrainian strikes killed three people in the Belgorod region and caused a fire at a warehouse belonging to Russian retailer Ozon, officials said.
A strike on the city of Sevastopol in Crimea killed one person, according to Sevastopol's Russian-installed governor.
US-led diplomatic efforts to end the conflict, Europe's deadliest since World War II, have been at a standstill for months.
Russia has demanded sweeping territorial and political concessions from Ukraine, which Kyiv has ruled out as tantamount to capitulation.
Earlier this week, US Central Intelligence Agency Director John Ratcliffe visited Moscow on an unannounced trip, amid escalating tensions in the four-and-a-half-year war.
