(Main article: Chemical weapons in World War I) The Gas attacks at Wulverghem in the municipality of Heuvelland were two German cloud gas attacks during World War I on British troops near Ypres in the Belgian province of West Flanders. The first gas discharge took place on 30 April 1916 and was followed by another attack on 17 June. The gas attacks at Wulverghem were part of the sporadic fighting, which took place between battles in the Ypres Salient on the Western Front. The British Second Army held the ground from Messines Ridge north to Steenstraat. British divisions opposite the German XXIII Reserve Corps, had received warnings of a gas attack in the ten days beforehand. From 21–23 April, British artillery-fire exploded several gas cylinders in the German lines around Spanbroekmolen, w