The Kremlin has since pointed blame at the US as UKraine are said to have used US-supplied ATACMS missiles.
The attack resulted in at least four fatalities and left 151 injured.
Kremlin spokesperson Dmitry Peskov posed a question to reporters: “You should ask my colleagues in Europe, and above all in Washington, the press secretaries, why their governments are killing Russian children.”
According to Russian officials, at least two children lost their lives in the attack on Sevastopol on Sunday. Footage showed people fleeing from a beach near Sevastopol, with some of the injured being carried away on sun loungers.
Kyiv has not commented on the attack but denies targeting civilians.