Twenty-one people have been killed from Russian shelling in Kherson, according to Ukraine's President Volodymyr Zelensky.
In a post on Telegram, the Ukrainian leader said 48 people had also been wounded in the attacks on the region.
It comes amid reports of a new wave of Russian airstrikes and explosions in Kyiv and the southern cities of Zaporizhzhia and Odessa.
The reports come just a day after Russia accuses Ukraine of trying to assassinate President Putin in a drone attack on the Kremlin; a claim which President Zelensky rejected. Western allies have also cast doubt on the report.
Speaking about attacks on the Kherson region, Zelensky posted on Telegram: "The world needs to see and know this.
"A railway station and a crossing, a house, a hardware store, a grocery supermarket, a gas station – do you know what unites these places? The bloody trail that Russia leaves with its shells, killing civilians in Kherson and Kherson region.
"As of now, 21 people have been killed! 48 wounded! All civilians! In one incomplete day! In one region! My condolences to the families and friends of the victims.
"We will never forgive the culprits. We will defeat evil state and hold all the perpetrators to account!"
Meanwhile, UK intelligence says a suspected drone strike caused a fire at a Russian fuel depot in Volna, on the Russian mainland side of the Kerch Strait, close to the Crimean bridge.
The intelligence suggests it follows a pattern of Russian fuel storage sites being damaged since the start of the year.