The residential block in the town of Chasiv Yar was hit on Saturday evening (Sunday AEST) as Russia once again ramped up its assault on cities and towns in eastern Ukraine in an attempt to take control over the entire Donbas area.
The State Emergency Service said that the bodies of 15 people had been found in the rubble so far and that the search and rescue works continued.
As of 1pm on Sunday (8pm AEST), emergency workers rescued five people and established contact with three others who were still buried under the rubble, the service said in a statement.
The emergency service added that 24 people, including one child, “may still be under the rubble”.
Pavlo Kyrylenko, the head of Donetsk regional military administration, told Ukrainian television that the area was struck by two or three Russian rockets and that the incident was “yet another confirmation of the crimes of the Russian Federation, confirmation that they are shelling residential areas”.
Chasiv Yar and other towns in Donetsk have been under heavy fire in recent days as Russian forces try to grind down Ukrainian resistance in the area and move further west.
Donetsk and Luhansk are the two regions that together form the Donbas, the eastern part of Ukraine where the conflict between Ukraine and Russian-backed separatists started in 2014.
The area has become the key centrepiece of Russian President Vladimir Putin’s military ambition in Ukraine after his troops failed to take over Kyiv earlier this year.
Russian troops have already taken over almost all of the Luhansk region, the head of Luhansk’s region military administration Serhiy Hayday said in a Telegram post on Saturday, adding that some 300,000 people from the area have been forced to flee their homes.
Lysychansk, the last city that was still under Ukrainian control in Luhansk, fell to Russia last week.
Russian troops have since focused on the Donetsk region, shelling wide areas along the front line and pushing from the Luhansk region into the Donetsk region, according to Hayday.
The Ukrainians have been defending this area against Russian attacks for more than a month.
“We are trying to contain the armed formations of the Russians along the entire front line,” Hayday said, adding that “the occupying forces achieved minor successes and continue their offensive to the west of Lysychansk.”