Iryna Dimitrieva thought she had found some semblance of safety and normality for her family, far from the frontline of war.

She was getting on with life as best she could – just like millions of other Ukrainians who are displaced within their own country.

Ms Dimitrieva proudly shared a video of her daughter Liza pushing a pink pram while toddling down a street in the city of Vinnytsia on Thursday morning.

Two hours later, that same pram was found upturned on the nature strip.

Liza’s body lay motionless on the ground. Beside her, a human foot.

Liza’s body was found beside her pram. Photo: Instagram

Ukrainian authorities said a Kalibr cruise missile had hit the city, 200 kilometres southwest of Kyiv. It was launched from a Russian submarine in the Black Sea.

Four-year-old Liza was one of at least three children killed that day. Her mum is in a critical condition in hospital and is yet to learn that her daughter did not survive.

“If I tell them that Liza is gone, I will bury them both,” Ms Dimitrieva’s mother Larisa told media from the hospital.

She said her daughter “Ira” had dedicated her life to raising Liza, who has Down’s syndrome.

President Volodymyr Zelenskiy’s wife Olena tweeted that she recognised the girl, who had once been among a group of children with disabilities who painted Christmas ornaments with the first lady.

Ukraine President Volodymyr Zelensky said the attack was “an open act of terrorism”. Photo: Getty

Liza’s speech pathologist remembered her as a “sunny flower” who was a “bright-eyed child, always cheerful”.

“Today, you became the ray of the sun,” the speech pathologist said.

A seven-year-old boy has also been identified as one of the 23 victims of that deadly attack.

Ukrainian journalists reported Maxim and his mother Victoria Rekuta had been at a medical appointment when the missile hit a nearby office building.

Officials said on Saturday morning (Australian time) that 352 children have now been confirmed dead as a result of attacks by Russian forces.

Another 657 have been wounded.

Maxim and his mother Victoria are among the 23 victims of the Vinnytsia attack. Photo: Instagram

The attack was the latest in a series of Russian strikes in recent weeks using long-range missiles on crowded buildings in cities full of civilians.

Russia’s defence ministry said the target of the attack was an office being used for a meeting between military officials and foreign arms suppliers.

It added: “The attack resulted in the elimination of the participants.”

Ukraine said the club functioned as a cultural centre.

The building also housed shops, commercial offices and a concert hall, where musicians were rehearsing for a pop concert planned for that night.

Meanwhile, Russian-backed separatists in eastern Ukraine said a British man in their custody had died of health problems.

The separatists, who captured 45-year-old Paul Urey, in April, had accused him of being a mercenary. Aid group Presidium Network said Mr Urey was working as a humanitarian volunteer helping rescue people at risk during the invasion.

Tweet from @KyivIndependent

Russian officials said Mr Urey had been given “appropriate” medical care – including for his diabetes – during his time in custody.

Mr Urey’s family, however, blame the Russian government for his death.

Presidium Network founder Dominic Byrne told the BBC that the captors had denied Mr Urey visits from medical teams from Red Cross.