Reinforcements began arriving to both sides, as fighting intensified, and the Russians launched an assault. During the first assault, the Russians suffered 4,000 casualties, while the Ottomans suffered 1,000. After this, Osman Pasha strengthened his defences. The Russians were reinforced by the army of Prince Carol I of Romania, who assumed command of the attacking army. On 31 July the Russians attacked Plevna again, but Ottoman troops managed to repulse the assault. After this second engagement, the Russians lost 10.000 men, while Ottomans lost 2,000. After suffering heavy casualties during the assault, the Russians sent out scouts, and resolved to cut off the Ottoman supply lines. To this end, Russian forces attacked the Ottoman garrison at Lovcha. This attack proved to be successful, and the Russians were able to cut off all communications and supply lines to Plevna. By now, Osman Pasha’s army had been reinforced to 30,000, while the Russian forces numbered 100,000. On 11 September, the Russians resumed the artillery bombardment, and mounted another assault. The assault succeeded in taking a few redoubts but Osman Pasha retook most of them. After the third battle, the Russians lost roughly 20,000 men, while the Ottomans lost only 5,000.