Farther south along the Sereth the Russian lines had been greatly strengthened by new troops brought up from the rear by means of the railroad Kieff-Shmerinka-Proskuroff-Tarnopol. This enabled the Russians to make determined attacks all along the river, which were especially severe in the neighborhood of Trembovla. General von Bothmer's German army at first successfully withstood these attacks in spite of Russian superiority in numbers, but was finally forced to withdraw from the west bank of the Sereth to the heights between that river and the Strypa River, which are between 750 and 1,000 feet above the sea level. But on September 9, 1915, the German forces advanced again and threw the Russians along almost the entire line again beyond the Sereth. Farther south on that river, near its junction with the Dniester, Austrian regiments under General Benigni and Prince Schoenburg stormed on the same day the Russian positions northwest of Szuparka, capturing over 4,000 Russians. While Von Mackensen's army was pushing its advance toward Pinsk, the principal city in the Pripet Marsh region, along both sides of the only railroad leading to it--the Brest-Litovsk-Kobryn-Pinsk-Gowel railroad line--heavy fighting continued in Volhynia and East Galicia. West of Kovno the Russians were thrown back of the Stubiel River on September 9, 1915, by the Austrians. General von Bothmer's German army, which formed the center of the forces in Volhynia and Galicia, advanced from Zaloshe on the Sereth toward Zbaraz, a few miles northeast of Tarnopol. Before the latter town, which the Russians seemed to be determined to hold at any cost, new reenforcements had appeared and opposed the advance of the Austro-German forces with the utmost fierceness. In that sector they passed from the defensive to the offensive, and with superior forces threw back the enemy again from the Sereth to the heights on the east bank of the Strypa on September 10, 1915. But with these heights at their back the German line held and all Russian attacks broke down. In spite of this they were renewed on September 11, 1915, with such strength that small detachments succeeded in gaining a temporary foothold in the enemy's trenches, where the bloodiest kind of hand-to-hand fighting occurred. At that moment General von Bothmer ordered an attack on both flanks of the Russians, who thereby were forced to give up the advantage which they had so dearly bought. However, this did not make the Russians lose heart. Again and again they came on, and so fierce were their onslaughts that the Austro-German line was finally withdrawn to the west bank of the Strypa on September 13, 1915. To the north, along the Ikwa from Dubno to the border, reenforcements were also brought up by the Russians and succeeded in holding up any further advance on the part of the Austrian troops. Especially hard fighting took place in the neighborhood of Novo Alexinez, a little village just across the border in Volhynia.