The town of Bakhmut in the Donetsk region, an important hub for the Ukrainian military, is coming under increasing attack from Russian missiles and artillery, according to Ukrainian officials.
Pavlo Kyrylenko, head of Donetsk regional military administration, said Thursday there had been another airstrike on the town, where some 20,000 people still live.
Kyrylenko said a five-story residential building and an office building had been hit and that so far six people have been rescued from the rubble.
"The Russians continue to fire at civilians, but timely evacuation allows us to save hundreds of lives," Kyrylenko said.
"Out of the 73,000 inhabitants of Bakhmut, just over 20,000 now remain in the city, thanks to which we are able to avoid the number of casualties that the enemy expects.
Once again, I ask everyone who has the opportunity to leave the Donetsk region. Now there are no absolutely safe places in Donetsk region," he added.
In recent days, Russian fire has intensified on places beyond the front lines in Donetsk, but Kyrylenko said Ukrainian units were resisting any advances on the ground.
"The enemy tried to make a breakthrough in the direction of Avdiyivka and Maryinka, on the route between Bakhmut and Lysychansk," but had been repelled and "retreated to previous positions," he said.
Some background: The Ukrainian military reported on Thursday that Russian forces trying to break through to Sloviansk, in eastern Ukraine's Donetsk region, had suffered losses and retreated.
Despite artillery and missile attacks by Russian forces on a wide front over the past 24 hours, there are no signs they have taken new territory.