A trio of Russian missiles slammed into the heart of a city in Ukraine on Thursday killing 12 people and wounding dozens.
Homes were obliterated in the blast along with an office block and a medical centre in the central city of Vinnytsia, according to national police.
Video footage showed thick black smoke billowing out of a tall building and sirens blaring as emergency workers rushed to the scene.
Officers said 90 people sought medical attention and around 50 of them were in a serious condition.
"There are wounded and dead, among them a small child," Ukrainian President Volodymyr Zelensky wrote on Telegram.
"What is this, if not an open act of terrorism?"
Grey smoke was seen rising from the twisted remains of burn-out cars and smouldering rubble in photographs released by the State Emergency Service.
One image showed an abandoned, overturned pram lying on the street.
"This is the act of Russian terror, 20 people died as of now," Zelensky said.
"Today in the morning, Russian missiles hit our city of Vinnytsia, an ordinary, peaceful city.
"Cruise missiles hit two community facilities, houses were destroyed, a medical centre was destroyed, the cars and trams were on fire."
The Russian defence ministry did not immediately comment on the reports from Vinnytsia.
Russia, which invaded Ukraine on February 24, has denied deliberately targeting civilians.
Vinnytsia lies about 125 miles southwest of the Ukrainian capital Kyiv and is far from the main frontlines in eastern and southern Ukraine.
The missile strike hit the car park of the nine-storey "Yuvelirniy" office block at around 10.50 am, the State Emergency Service said.
"Unfortunately, there is probably no chance of finding anyone who survived under the rubble," a senior regional emergency service official told Ukrainian television.
In a comment on Twitter, Foreign Minister Dmytro Kuleba accused Russia of committing "another war crime".
"We will put Russian war criminals on trial for every drop of Ukrainian blood and tears," he wrote.
Russia denies its forces have committed war crimes in Ukraine.
The Kremlin said it is engaged in a "special military operation" to demilitarise Ukraine and root out what it regards as dangerous nationalists.
While Kyiv and its Western allies reject that as a false pretext for an unprovoked war of aggression.
