-Russia said on Monday that it had used cruise missiles to destroy S-300 anti-aircraft missile systems which had been supplied to Ukraine by an unidentified European country.
Russia launched Kalibr cruise missiles on Sunday against four S-300 launchers which were concealed in a hangar on the outskirts of the Ukrainian city of Dnipro, the defence ministry said.
Russia said 25 Ukrainian troops were hit in the attack.
"High-precision sea-launched Kalibr missiles destroyed the equipment of a S-300 anti-aircraft missile division which had been delivered to the Kyiv regime by a European country," the ministry said.
Russia did not say which European country had supplied the S-300 systems.
NATO member Slovakia, which had donated such a missile system to Ukraine, said the one it supplied had not been hit.
"Our S-300 was not destroyed," Slovak government spokesperson Lubica Janikova said.
Russian forces also shot down two Ukrainian Su-25 aircraft near the city of Izium and destroyed two ammunition depots, one of which was near the southern city of Mykolaiv, the Russian defence ministry said.
The Ukrainian military did not immediately respond to a request for comment.