Russian forces dig in as bloody Ukrainian counterattack anticipated in south

Strikes indicate huge battle' may be on way that will be a key test of Kyiv troops' ability to push Russia back

• Russia-Ukraine war: latest updates

The war in Ukraine may be heading for its bloodiest phase yet, according to senior Ukrainian officials and western analysts, who say a long-threatened southern counteroffensive by Kyiv's forces will result in a huge battle" and will need to overcome increasingly well dug-in Russian troops.

People interviewed by the Guardian, including those who have recently escaped Kherson, describe Russian forces in the south building hardened tank shelters, digging trenches and bringing in prefabricated concrete pillboxes by lorry.