The sound of artillery battles could be heard in villages all along the front line in southern Ukraine on Wednesday. Ukrainian guns fired steadily from hidden positions and Russian artillery and mortars targeted former Russian positions and villages now occupied by Ukrainian soldiers.

Ukrainian troops deployed along the southern front as part of the counteroffensive say they are steadily pushing the Russian troops back, but they describe their progress as step-by-step, rather than breakthrough movements.

The front in Zaporizhzhia is one of three axes of Ukraine’s counteroffensive. One Ukrainian military objective is to reach the Sea of Azov, driving a wedge between Russian-occupied territories in southern and eastern Ukraine.

But Russian forces have built a layered defence of minefields, tank traps and fortified positions that stretches along the length of the front line and runs at least 32km deep. In the two months since their counteroffensive began, the Ukrainians have had to cross these heavily mined fields and tree lines to take dug-in Russian positions, while coming under heavy bombardment.

The devastating artillery fire and powerful aviation bombs have hampered them the most, soldiers said.

On Wednesday morning a Ukrainian jet flew low over the front line, firing rockets at Russian positions before banking away sharply and releasing flares to deflect any anti-aircraft fire. Some of Ukraine’s newly trained brigades, many of them equipped with western armoured fighting vehicles, are engaged in the fighting.