Russian forces attacked Kostiantynivka in Donetsk Oblast on July 24 with cluster munitions, killing a child and injuring at least six people, including three other children, Governor Pavlo Kyrylenko reported.
"Around 7 p.m., Russians opened fire while people were relaxing at a beach," Kyrylenko wrote on Telegram.
According to the governor, Russia used Smerch multiple-launch rocket systems with cluster munitions in the attack against civilians.
The wounded victims included four children: girls aged 5, 11, and 12, and an 11-old-year boy. Kyrylenko later wrote that the boy died.
The attack comes among increasingly frequent reports of Russian use of cluster munitions in eastern Ukraine.
On July 23, Russian forces used cluster munitions in a double-tap strike against an aid center in Chasiv Yar, another town in Donetsk Oblast. The governor said the attack started a fire but no causalities were reported.
Deutsche Welle cameraman Yevgeny Shilko was wounded by Russian cluster munitions in the city of Druzhkivka on July 22. The attack also killed one Ukrainian soldier and injured several more people.
As the Ukrainian military deployed U.S.-provided cluster munitions against Russian positions, the Kremlin uses its own arsenal against Ukrainian civilians in retaliation.
Ukrainian officials and human rights groups have said that Russia has already indiscriminately used cluster munitions against civilian targets since last year.