Kateryna Velnychuk was having an afternoon nap when an explosion shattered the windows of her ground-floor flat, spraying shrapnel that tore holes through her walls and cupboards.

A Russian guided bomb had exploded in the courtyard outside the five-storey Soviet-era building, killing a postman on his rounds. As her flat filled with thick, milky smoke, the 22-year-old turned to see blood pouring from her boyfriend Vladyslav¡¯s head.

¡°As we¡¯ve been living ... in a state of war, there was no sense of fear in the moment,¡± Velnychuk said. ¡°You just understand there was an explosion. The only thought in your head is ¡®I hope we survive.¡¯¡± As Russia has intensified its air campaign against Ukraine in the last month, hammering its energy infrastructure and urban areas, no major city has been harder hit than Kharkiv.