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.
The grief of parents
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.
'Show this to Putin'
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."
Hospital without power
Smoke from shelling rises over a snow-covered residential part of Mariupol, while in the city's hospital, the bangs send women dropping to the floor for shelter. One raises her arms in prayer.
Doctors use their smartphone torches to examine patients' wounds, as the hospital lacks electricity and heating.
"We work more than a week without a break, [some of us] even more," Dr. Evgeniy Dubrov said. "[We] continue working, everyone on their positions."
Grappling with the pain of their wounds, Ukrainian soldiers are in shock at the loss of their comrades.
"I don't understand what had happened, blast, my eyes getting dark and vision blurring," Svyatoslav Borodin said. "I continued to crawl ... but I didn't understand if I had legs or not. Then I turned and saw my leg."
Death on a soccer field
Flashes from shelling light up the medics as they stand in a parking lot waiting for the next emergency call.
In the hospital nearby, a father buries his face into his dead 16-year-old son's head. The boy, draped under a bloodstained sheet, has succumbed to wounds from shelling on the soccer field where he was playing.
Hospital staff wipe blood off a gurney. Others treat a man whose face is obscured by blood-soaked bandages.
The medics prepare to go out, strapping on their helmets.
Children still play
A resting toddler, perhaps responding instinctively to the sight of a camera, raises an arm and waves. But the mother underneath has tears in her eyes. They're lying together on the floor in a gym-turned-shelter, waiting out the fighting that rages outside.
Many families have young children. And as children do anywhere, some giggle and run around the floor covered with blankets.
"God forbid that any rockets hit. That's why we've gathered everyone here," said local volunteer Ervand Tovmasyan, accompanied by his young son.
He says locals have brought supplies. But as the Russian siege continues, the shelter lacks enough drinking water, food and gasoline for generators.
Basement nursery doubles as a bomb shelter
A nurse fits a shirt on a newborn who fusses at first and then cries loudly. It is a joyful sound.
Babies born at a Mariupol hospital are taken down flights of stairs to a makeshift nursery that also serves as a bomb shelter during shelling.
Sitting in the dimly lit shelter, new mother Kateryna Suharokova struggles to control her emotions as she holds her son, Makar.
"I was anxious, anxious about giving birth to the baby in these times," the 30-year-old said, her voice shaking. "I'm thankful to the doctors who helped this baby to be born in these conditions. I believe that everything will be fine."
Above the basement, hospital staff labour to save people wounded in the shelling. A woman with blood streaming from her mouth cries out in pain, A young man's face is ashen as he is wheeled into the hospital. Another, who did not survive, is covered by a thin blue sheet.
"Do I need to say more?" asked Dr. Oleksandr Balash, head of the anesthesiology department.
"This is just a boy."