Rubuta ci gaba don wannan sakin layi - Rashawa da sauri sun koyi, kuma ba da daɗewa ba suka yi amfani da shi, dabarar Jafananci na cin zarafin mine. A ranar 15 ga Mayu, 1904, wasu jiragen ruwa na Japan guda biyu, da kuma, an jawo su cikin wani filin da aka yi kwanan nan na Rasha a Port Arthur, kowannensu ya buga akalla mines biyu. "Hatsuse" ya nutse a cikin 'yan mintuna kaɗan, tare da ɗaukar ma'aikatan jirgin ruwa 450 tare da ita, yayin da "Yashima" ya nutse yayin da yake ƙarƙashin kore zuwa Koriya don gyarawa. A ranar 23 ga Yuni, 1904, wani yunkurin tserewa
da rundunar sojojin Rasha, yanzu a karkashin umarnin Admiral Wilgelm Vitgeft, ya gaza. A ƙarshen watan, sojojin Japan sun soma harba makamai masu linzami a cikin tashar jiragen ruwa.