A Russian missile attack on apartment buildings in the eastern Ukrainian region of Donetsk has killed at least 15 people.

Saturday night's strike destroyed five-story buildings in a town about 30 kilometers southeast of the Ukrainian stronghold of Kramatorsk.

Ukraine's Emergency Services said that at least 15 people were killed and five others injured.

Video footage taken the following day shows rescuers pulling out a man trapped under the rubble. The man was laid on a stretcher and taken to a hospital.

Ukraine's state-run media quoted the deputy head of the presidential office, Kyrylo Tymoshenko, as saying that 23 people, including a child, remain under the rubble.

President Volodymyr Zelenskyy said in a video message on Sunday, "There are 15 names in the list of the dead and, unfortunately, this is not the final number."

He also said, "Everyone who gives orders for such strikes, everyone who carries them out targeting our ordinary cities, residential areas, kills absolutely deliberately."

He added, "punishment is inevitable for every Russian murderer."

Meanwhile, Russia's defense ministry said on Sunday that its troops attacked the Ukrainian stronghold of Sloviansk in the Donetsk region, killing up to 100 Ukrainian soldiers and destroying US-produced artillery ammunitions and rocket shells.

Russia appears to be reinforcing its troops and replenishing military supplies to launch further large-scale offensives on key Ukrainian cities as it attempts to take full control of Donetsk.