The German 4th Army operation order for the defensive battle was issued on 27 June. German infantry units had been reorganised on similar lines to the British, with a rifle section, assault troop section, a grenade-launcher section and a light machine-gun section. Field artillery in the divisions had been organised into artillery assault groups, which followed the infantry to engage the attackers with observed or direct fire. Each infantry regiment of the 183rd Division, based around Westroosebeke behind the northern flank of Group Ypres, had a battalion of the divisional field artillery regiment attached. From mid-1917, the area east of Ypres was defended by six German defensive positions: the front position, (second position), (third position), (fourth position), (fifth position) and (under construction).