while the main actions were playing out in the north, xxx corps alternated between attack and defence. the soviet forces held the sapun ridge and could observe german movements. on occasion they could deliver effective counter battery fire. between the 21–28 june, the germans lost 10 artillery pieces, including five 150 mm s. fh 18 medium howitzers. in the centre, the romanians took up the slack. the 18th infantry, 1st, and 4th mountain divisions, supported by 100 guns, gradually advanced up the chernaya river towards the mouth of the river and severnaya bay. with support from liv corps on its left, the axis captured all the soviet defensive lines east of the chernaya river.