"Moskva" was commissioned in 1938 and twice made port visits in Turkey before Operation Barbarossa began on 22 June 1941. Both "Moskva" and "Kharkov" bombarded the Romanian port of Constanţa with a total of 350 rounds on 26 June, but "Moskva" was sunk. Between 16 and 19 June, the Romanian minelayers "Amiral Murgescu", "Regele Carol I" and "Aurora" laid a barrage of 1,000 mines near the port of Constanţa, (although other causes have been suggested: shells from the Romanian destroyer "Regina Maria" and the German coast defense battery "Tirpitz", or an accidental friendly fire torpedo attack by the Soviet submarine "Shch-206".)