Mariupol diary: Scenes from Ukrainian port city battered by Russia's invasion

WARNING: This story contains graphic images and details about Ukrainians wounded and killed by Russian attacks.

A man dashes into a hospital with a desperately wounded toddler in his arms, the child's mother on his heels.

New mothers nestle infants in makeshift basement bomb shelters. 

A father collapses in grief over the death of his teenage son when shelling ravages a soccer field near a school.

These scenes unfolded in and around the Azov Sea port city of Mariupol in southern Ukraine over the past week, captured by Associated Press journalists documenting Russia's invasion.

With nighttime temperatures just above freezing, the battle plunged the city into darkness late in the week, knocked out most phone services and raised the prospect of food and water shortages. Without phone connections, medics did not know where to take the wounded.

A limited ceasefire that Russia declared to let civilians evacuate Mariupol and Volnovakha, a city to its north, quickly fell apart on Saturday, with Ukrainian officials blaming Russian shelling for blocking the promised safe passage.

Russia has made significant gains on the ground in the south in an apparent bid to cut off Ukraine's access to the sea. Capturing Mariupol could allow Russia to build a land corridor to Crimea, which it seized in 2014.

A man dashes through the doors of a hospital carrying a desperately wounded toddler wrapped in a pale blue, bloodstained blanket. His girlfriend, the baby's mother, is on his heels.

Hospital workers surge around, trying to save the life of 18-month-old Kirill, but there is nothing to be done. 

As Marina Yatsko and her boyfriend, Fedor, weep in each other's arms, distraught staff sit on the floor and try to recover themselves before the next emergency arrives.

It's a scene repeated over and over again in Mariupol. Days earlier, hospital workers had pulled a wounded six-year-old girl from an ambulance as her mother stood alone, helpless.

Multiple attempts at resuscitation failed until eventually the frenetic activity stopped and the mother was left with her grief. A doctor looked straight into the camera of an AP videojournalist allowed inside.

He had a message: "Show this to Putin."