In the hamlet of Dmytrivka to the west of the capital on Friday, smoke was still rising from the wrecks of tanks and the bodies of at least eight Russian soldiers lay in the streets, Reuters correspondents saw.
"From one side we were hearing the tanks shooting at us, and from the area of Bucha was a massive mortar shelling," said resident Leonid Vereshchagin, a business executive, referring to a town to the north.
Ukrainian forces went on to take back Bucha, its mayor said on Friday in a video that appeared to be filmed outside the town hall. The advances followed several days of Ukrainian gains around Kyiv and in the north.
In southwest Ukraine, three rockets hit a residential district in the region of Odesa, causing casualties, its governor Maksym Marchenko said, without specifying how many. Russia denies targeting civilians.
Marchenko said the missiles were fired from an Iskander missile system in Crimea, the southern Ukrainian peninsula annexed by Russia in 2014.
President Vladimir Putin sent troops on February 24 for what he calls a "special operation" to demilitarise Ukraine. The West calls it an unprovoked war of aggression that has killed thousands and uprooted a quarter of Ukraine's population.
In the Russian border city of Belgorod, a logistics hub for its war effort, Moscow said Ukrainian helicopters struck a fuel depot, causing a huge fire. Ukraine denied responsibility for the incident, the first of its kind in the five-week-old war.
The fire destroyed several oil tanks and would likely add short-term strain to Russia's already stretched logistics chains, Britain's defence ministry said.
Kremlin spokesman Dmitry Peskov said the incident could jeopardise Ukrainian-Russian peace talks, which resumed on Friday by video link. Russia would strengthen its western borders so it would not "cross anyone's mind to attack", Peskov said later.
Ukraine's top security official said Russia's accusations were not correct. Ukraine's defence ministry earlier had declined to confirm or deny involvement.
A Russian threat to cut off gas supplies to Europe unless buyers paid with roubles by Friday was averted for now, with Moscow saying it would not halt supplies until new payments are due later in April.
Russia says the southeastern region of Donbas, where it has backed separatists since 2014, is now the focus of its war efforts. The besieged and bombarded Azov Sea port city of Mariupol has been its main target there.
Conditions on Friday made it impossible to go ahead with a plan to evacuate civilians from Mariupol, where tens of thousands are trapped with scant water or food, the International Committee of the Red Cross said.
UN aid chief Martin Griffiths will travel to Moscow on Sunday and then to Kyiv as the United Nations pursues a humanitarian ceasefire in Ukraine, UN Secretary-General Antonio Guterres told reporters.
A total of 6266 people fled Ukrainian cities through humanitarian corridors on Friday, said Kyrylo Tymoshenko, deputy head of the Ukrainian president's office.
After failing to capture a single major city, Russia has painted its draw-down of forces near Kyiv as a goodwill gesture in peace talks. The negotiations led to a prisoner exchange on Friday, Tymoshenko said, with the release of 86 Ukrainian troops.
Tymoshenko did not say how many Russian soldiers were released.
Ukraine and its allies say Russian forces have been forced to regroup after suffering heavy losses due to determined Ukrainian resistance.
Regional governors in Kyiv and Chernihiv said Russians were pulling out of areas in both those provinces, some heading back across borders to Belarus and Russia.
