A "massive attack" of Russian missiles killed six people on Sunday in residential areas of Kostyantynivka, near Bakhmut, in eastern Ukraine as President Volodymyr Zelensky hailed the resistance against what he called "the biggest force against humanity of our time".
Zelensky was speaking on the first anniversary of the discovery of bodies of civilians killed in Bucha, a town near Kyiv that has become a symbol of the alleged war crimes carried out by Moscow during the invasion.
Russia has accused Ukraine and its allies of staging the atrocities.
Sunday's macabre anniversary comes a day after Russia took over the rotating presidency of the UN Security Council despite outrage from Kyiv and Western nations that have imposed sanctions on Moscow.
Fierce clashes continue around Bakhmut, which has been at the epicenter of the fighting for months.
In Kostyantynivka, about 27 kilometers (17 miles) from Bakhmut -- a city now in ruins -- a Russian bombardment left three men and three women dead and eleven wounded, Ukrainian authorities said.
These are "just residential areas", "ordinary civilians of an ordinary city of Donbas" who were targeted, Zelensky said.
There was a large crater in a yard and windows were shattered from ground to top floors in two 14-story tower blocks, while private homes nearby had smashed roofs, AFP journalists saw.