"At least eight residential buildings were damaged.
One of them was completely destroyed," the local police wrote in a Facebook post, according to the Reuters news agency.
The president of Ukraine, Volodymyr Zelenskyy, writes in a Twitter post that civilians have been affected by the attack.
“Russian terrorists have hit the city with a ballistic robot resulting in civilian casualties.
Some people are still under the rubble.
No other goal than terror," he writes.
Zelensky also reiterates Kiev's plea for more and heavier weapons from the West.
"The only way to stop Russian terrorism is to defeat it.
With tanks.
Fighter aircraft.
Long-distance robots," he continues.
Kramatorsk is one of the largest cities in the Donetsk region of southeastern Ukraine.
In January, 44 people died in a Russian attack on a residential building in the city of Dnipro in the eastern part of the country.
Ukraine accuses Russia of indiscriminately attacking civilian targets, a charge Moscow routinely denies.