Russian soldiers captured in the battle for Avdiivka tell of the high price their army is incurring for its grinding advance.

Avdiivka, a former coal hub in the eastern Donetsk region, has become a symbol of a grinding war in which neither Ukraine nor Russia has made a decisive breakthrough in more than a year. Around 1,350 people still live amongst its destroyed buildings and ruined apartment blocks, compared to 30,000 before the war -- the few still refusing to leave despite Russia's attacks.