General Nivelle reported that over 10,000 prisoners were captured during this offensive together with a vast amount of war material. Meanwhile the British in the Lens area were constantly engaged with the Germans, who again and again launched counterattacks to recover lost positions, to impede the advance and to gain time to strengthen their defenses on the line of retreat. During the night of April 15, 1917, the British captured Villeret, southeast of Hargicourt, which served to further widen the second gap in the Hindenburg line north of St. Quentin. The British were successful in all these minor struggles in making prisoners, and owing to the Germans' hurried retreat vast quantities of military stores fell into their hands. Since April 9, 1917, the British had captured over 14,000 prisoners and 194 guns. In the midst of a driving rain and flurries of snow that hampered military operations the French struck another blow on the 17th, on a new eleven-mile stretch of front east of Rheims from Prunay to Auberive. They carried the entire front-line German positions. From Mt. Carnillet to Vaudesincourt support positions seven miles in extent also were captured. During this push 2,500 German prisoners were taken. The French advance on both sides of Rheims now left that city in a salient that would prove a great source of danger to the Germans. The French having captured the German second-line position northwest of Rheims, smoothed the way for an advance that might force the enemy out of the forts that held the cathedral city in subjection. The French continued their offensive with undiminished vigor and dash on April 18, 1917, driving the Germans in disorder from their positions north of the Aisne and securing a firm hold on high ground commanding the river. The number of German prisoners had now increased to 20,730. Great quantities of war material fell to the French, including 175 guns, 412 machine guns, and 119 trench mortars. On the front from Soissons to Rheims General Nivelle's troops captured four villages, which brought them to the outskirts of Courtecon, an advance of about two miles for the day. Another successful French attack was delivered to the west, where the old German line stood on the south bank of the Aisne, which resulted in the capture of the important town of Vailly and a strong bridgehead near by. On the western leg of the German salient, whose apex was at Fort Conde on the Aisne, the French struck another decisive blow which gave them the village of Nanteuil-le-Fosse, and endangered the Germans in the fort, who were now in the position of being cut off. East of Craonne a French contingent surrounded the forest of La Ville-au-Bois and forced the surrender of 1,300 Germans.