Russian shelling killed seven people, including a 22-day-old infant, and wounded at least 22 in Ukraine's southern region of Kherson on Sunday, prompting local officials to declare Monday a day of mourning and President Volodymyr Zelenskiy to promise justice.

Kyiv reclaimed part of Kherson from Russian occupation last November but Kremlin troops have continued shelling the regional capital and areas around it from across the Dnipro River.

Five people were killed in the village of Shyroka Balka, including a 22-day-old girl, her 12-year-old brother who died from serious injuries in hospital, and their 39-year-old mother, Olesia, Zelenskiy said.

"The terrorists will never willingly stop killing civilians," Interior Minister Ihor Klymenko wrote in a Telegram post. "The terrorists must be stopped. With force. They don't understand anything else."

Two people, including the pastor of a church, were killed in the neighbouring village of Stanislav, according to Governor Oleksandr Prokudin.

Three people each in Kherson city and the town of Beryslav were wounded, according to the interior ministry, and casualties were also reported in five other settlements across the region.

"Today the Kherson region shuddered from terrible news. Kherson, Veletenske, Zolota Balka, Stanislav, Komyshany, Shyroka Balka..." Prokudin wrote on Telegram, listing the settlements hit in Sunday's attacks.

Later in the evening, the local Kherson government said a new air strike and artillery shelling had injured a 31-year-old woman and a man and damaged at least 12 houses in the town of Bilozerka. In a Telegram post, it said three guided aerial bombs had damaged several houses in the village of Odradokamianka.

Zelenskiy said that by 6 p.m. there had been 17 reports of shelling in Kherson region alone on Sunday, as well as incidents in the regions of Mykolaiv, Zaporizhzhia, Donbas, Kharkiv, and in border areas in northeast Ukraine.

"There is no day when Russian evil does not receive our entirely just response," he said in his nightly video address.

He named past Russian targets, including occupiers, equipment, depots, and the Kerch Bridge linking occupied Crimea with Russia that his domestic intelligence agency recently acknowledged sabotaging last October, as "evidence that we will not leave any of Russia's crimes unanswered."

Ukraine's military launched a counteroffensive in June to reclaim Russian-occupied territory across the southeast but has not made any significant attempts to cross the Dnipro to reach the other side of the Kherson region.

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