Back the Germans and Austrians forced their retreating enemy during the following days, although the pursuit lost a little in force and swiftness. For the troops which were engaged in these operations had been steadily on the move practically ever since the attack on Warsaw began. On September 6-7, 1915, the Russians again made a stand on a wide front east and south of Grodno. This line stretched south from the Niemen near Mosty to Volkovysk, then southeast to Rushana, thence east of the Pushany Marshes across the Jasiolda River near Chenisk to Drohichyn, on the Brest-Litovsk-Pinsk railroad. On the German and Austrian side these engagements were fought by the armies of Prince Leopold of Bavaria and Field Marshal von Mackensen. At the same time troops belonging to Von Hindenburg's group attacked a newly formed Russian line farther north which extended from Volkovysk in a northwesterly direction to the village of Jeziory and the small lake on which the latter is situated, just north of Grodno. Volkovysk itself and the heights northeast of it were stormed by the Germans on September 7, 1915, on which occasion again almost 3,000 Russians were captured by the Germans. During the next few days the left wing of this army group fought in close cooperation with the right wing of Von Hindenburg's army along the upper Zelvianka, a southern tributary of the Niemen. The rest of Prince Leopold's army were making the Kobryn-Minsk railroad their objective and were fighting on September 9, 10, and 11, 1915, for possession of the station at Kossovo.