AT a cemetery outside Mariupol, a Ukrainian city captured by Russia last week after a destructive three-month siege, a grief-stricken mother sobs inconsolably.

Natalya lost her only son, Vladimir Voloshin, on March 26 when shrapnel smashed into his skull and chest in the fight for the city. He was 28.

Wearing a headscarf to hold back her flowing white curls, the 57-year-old nurse said Vladimir had recently graduated from a local naval academy. What seemed like a promising career was upended overnight when Ukraine announced a general mobilisation to counter the Russian invasion.

"He had been supposed to set sail in February," Natalya said on Sunday between sobs at the cemetery in Staryi Krym, just north of Mariupol, where her son was laid to rest.

"But then the war started. For no reason at all."

Russia sent thousands of troops into Ukraine on Feb. 24, saying it had to counter a military threat and rid Ukraine of nationalists threatening Russian speakers - claims dismissed by Kyiv and Western countries as false pretexts for a land grab.

Mariupol, a once bustling port city on the Sea of Azov in southeastern Ukraine quickly became a Russian target. After a siege that Ukraine says killed tens of thousands, it has now succumbed to occupation and lies in ruins.

Treading through long rows of fresh graves and makeshift wooden crosses, Natalya said many of Mariupol's dead had no one left to honour their memory.

"Who will bury them? Who will put up a plaque?" she asked. "They have no family."