Thirty-seven people have died and almost 400 evacuated after a Russian drone strike hit a depot storing weapons for Ukraine's military near a residential area.
President Volodymyr Zelensky said the strike caused shells, mines and drones to detonate late on Friday, triggering a blast which damaged nearby properties including a "care home for elderly people and people with disabilities".
An investigation into the "terrible negligence on the part of those who stored explosive right next to people" has begun, he said.
Four children are among 42 people injured, according to regional head Tymur Tkachenko, with a rescue operation ongoing at the site in the Bucha district on Saturday.
"Criminal proceedings have been opened on charges of official negligence," Zelensky said.
The office of Ukraine's prosecutor general earlier said it was reviewing the "legality of the placement and storage of explosive objects and materials" near residential buildings in the village of Myla, to the west of the capital Kyiv.
It said the "actions of officials who made the relevant decisions" would also be investigated.
Russia's Ministry of Defence said in a statement that its forces had targeted "an ammunition depot" in Myla which stored "components and launch boosters for FP-1/FP-2 long-range unmanned aerial vehicles".
Reuters
An investigation has been launched into whether ammunition was being stored in the warehouse to the west of the capital
Meanwhile, Tkachenko said a 14-year-old was killed in a separate attack in the Boryspil district while Kyiv Mayor Vitaliy Klitschko said a two-year-old had died after a Russian drone crashed in Obolonskyi.
He added that five people, including an 18-year-old girl, were injured in fresh strikes on the capital on Saturday morning. Five people have been killed across the country over the past day, according to local officials.
Zelensky reported further overnight strikes in Odesa, Dnipropetrovsk, Sumy and Zaporizhzhia, as the Ukrainian army said it had shot down 233 Russian drones.
In Russia, local officials said two people had been killed and 25 injured in strikes in the Belgorod and Rostov regions in the past 24 hours.
The Moscow-appointed governor of the occupied Ukrainian region of Zaphorizhzhia said four people were injured after a Ukrainian strike hit a shopping centre.
Russian online retailer Ozon said one of its logistic centres had been hit in an overnight Ukrainian drone strike. It said it had also suspended operations at a second logistics centre and evacuate staff "due to the danger in the area".
The retailer's facilities in Krasnodar, Dagestan, Stavropol and Adygea were targeted in strikes earlier this week, resulting in several injuries and widespread damage.
Russia and Ukraine have been intensifying their attacks in recent months, with Kyiv focusing its operations on Russian economic targets.
Ukraine has for weeks struck sites belonging to Wildberries, the country's biggest online retailer, describing the firm as a legitimate target because it supplied components to the military, which Moscow denies.
