In the port city of Mariupol, where Ukrainians were trying to fend off a Russian advance on Sunday, an ambulance raced into a city hospital carrying a six-year-old girl hit during Russian shelling.
Warning: This story contains graphic details and imagery.
She was pale. Her brown hair was pulled back with a rubber band. Her bloody pyjama pants were decorated with cartoon unicorns.
A medical team pumped her chest, fighting desperately to revive her. Her mother stood outside the ambulance, weeping.
"Take her out! Take her out! We can make it!" a hospital worker shouted, pushing a gurney to the ambulance.
The girl was raced inside and doctors and nurses huddled around her. One gave her an injection. Another tried to revive her with a defibrillator. A nurse wept.
A doctor in blue medical scrubs, pumping oxygen into her, looked straight at the camera of an Associated Press video journalist who had been allowed inside.
"Show this to Putin," he said angrily, standing next to the girl who didn't survive.
"The eyes of this child, and crying doctors."
Civilian death toll continues to climb
While on the global stage, Russian President Vladimir Putin responded to increased international efforts with threats to go nuclear, on the ground, Russian attacks on Ukrainian cities using more conventional warfare continued.
Ukraine's Health Ministry said at least 352 civilians had been killed and 1,684 wounded during the invasion as of Sunday local time.
On Monday, Ukranian President Volodymyr Zelenskyy said 16 children had been killed and 45 wounded.
The numbers have not been independently verified.
Russia has said that its troops are targeting only Ukrainian military facilities and that Ukraine's civilian population is not in danger.
However, at least 102 civilians in Ukraine have been killed since Russia launched its invasion last Thursday, with a further 304 injured, but the real figure is feared to be "considerably higher", UN human rights chief Michelle Bachelet said on Monday (local time).
"Most of these civilians were killed by explosive weapons with a wide-impact area, including shelling from heavy artillery and multi-launch rocket systems, and air strikes," she said.
The girl in the unicorn pyjamas, whose name was not immediately known, was just one of those deaths.
Her body was left alone in the hospital room, covered by her brightly coloured polyester jacket, now spattered with blood.
Ms Bachelet says some 422,000 Ukrainians have fled their homeland, with many more displaced within the country.
More than 280,000 have fled into neighbouring Poland.
Talks over Ukraine crisis
Mr Zelenskyy, meanwhile, agreed to talks with Moscow, and Western nations planned to send arms and other supplies to the country's defenders.
Ukraine said negotiations with Moscow, without preconditions, would be held at on the Belarusian-Ukrainian border.
Russian news agency Tass cited an unidentified source as saying the talks would start on Monday morning (local time).
The Vatican also offered to "facilitate dialogue" between Russia and Ukraine.
US President Joe Biden will host a call with allies and partners on Monday to coordinate a united response, the White House said.
Western nations said they would tighten sanctions and buy and deliver weapons for Ukraine, including Stinger missiles for shooting down helicopters and other aircraft.
European countries will also supply fighter jets to Ukraine, EU foreign policy chief Josep Borrell said.
'I wish I had never lived to see this'
Nearly 900 kilometres away from Mariupol in the city of Chernihiv, Faina Bystritska has been living in a hallway, away from any windows, so she can better protect herself.
"I wish I had never lived to see this," the 87-year-old Jewish survivor of World War II said. She said sirens blared almost constantly in the city.
Chernihiv residents had been told not to switch on any lights "so we don’t draw their attention", Ms Bystritska said.
"The window glass constantly shakes, and there is this constant thundering noise," she said.
'I just want the shooting to stop'
In downtown Kharkiv, in north-eastern Ukraine, 86-year-old Olena Dudnik said she and her husband were nearly thrown from their bed by the pressure blast from a nearby explosion.
The Ukrainian state news agency on Sunday said Russian troops blew up a natural gas pipeline in the city, Ukraine's second largest, sending a burning cloud into the sky.
Soon after, Russian armoured vehicles rolled into the city, with witnesses reporting firing and explosions. But city authorities said the attack had been repelled.
Reuters was unable to corroborate the information.
"Every day there are street fights, even downtown," with Ukrainian fighters trying to stop Russian tanks, armoured vehicles and missile launchers, Ms Dudnik said by phone.
She said the lines at drugstores were hours long.
"We are suffering immensely," she said.
"We don't have much food in the pantry and I worry the stores aren't going to have anything either — if they reopen."
She added: "I just want the shooting to stop, people to stop being killed."
Russians to 'learn and adapt'
Mr Putin's directive to put nuclear force on high alert came as Russian forces encountered strong opposition from Ukraine defenders.
Moscow has so far failed to win full control of Ukraine's airspace, despite advancing across the country.
The fast-moving developments came as scattered fighting was reported in Kyiv.
Battles also broke out in Ukraine's second-largest city, Kharkiv, and strategic ports in the country's south came under assault from Russian forces.
By late Sunday, Russian forces had taken Berdyansk, a Ukrainian city of 100,000 on the Azov Sea coast, according to Oleksiy Arestovich, an adviser to President Zelenskyy.
Russian troops also made advances toward Kherson, another city in the south of Ukraine, while Mariupol, the port city on the Sea of Azov which is considered a prime Russian target, was "hanging on", Mr Arestovich said.
Pentagon officials said Russian troops were being slowed by Ukrainian resistance, fuel shortages and other logistical problems, and that Ukraine's air defence systems, while weakened, were still operating.
But a senior US defence official told AP that would probably change: "We are in day four. The Russians will learn and adapt."
Kyiv quiet after assault
Kyiv was eerily quiet on Sunday afternoon, after explosions lit up the morning sky and authorities reported blasts at an airport.
A main boulevard was practically deserted as a strict curfew kept people off the streets.
Authorities warned that anyone venturing out without a pass would be considered a Russian saboteur.
Terrified residents hunkered down in homes, underground garages and subway stations in anticipation of a full-scale Russian assault.
Satellite imagery released by private company Maxar Technologies taken on Sunday showed a 5km-long convoy of Russian ground forces, including tanks, approximately 64km away and heading towards Kyiv.
Warning of a 'humanitarian catastrophe'
Kyiv Mayor Vitali Klitschko said food and medicine were already running low.
Authorities have been handing out weapons to anyone willing to defend the city.
"Right now, the most important question is to defend our country," Mr Klitschko said.
Responding to a question about the city's capacity to replenish dwindling stocks of food and medicine, Mr Klitschko's view darkened.
"We are at the border of a humanitarian catastrophe," he said.
"Right now, we have electricity, right now we have water and heating in our houses. But the infrastructure is destroyed to deliver the food and medication."
ABC/wires
