Russian forces are continuing their attempts to seize full control of the Luhansk region of eastern Ukraine.
Russian troops are believed to have taken control of most parts of Luhansk. They are shelling the Ukrainian stronghold of Severodonetsk, as well as Lysychansk.
Serhiy Haidai, the governor of the Luhansk region, said in a social media post on Sunday that Russian forces have been shelling residential areas with large-caliber artillery for hours. But he added that Ukrainians are able to put up with the Russian attacks.
Footage taken in Lysychansk on Saturday shows Ukrainian soldiers helping civilians to evacuate during artillery attacks.
On Sunday, Russian President Vladimir Putin called on citizens to unite in a speech he gave at an event in Moscow to celebrate "Russia Day".
The national holiday marks Russia's declaration of sovereignty from the former Soviet Union in 1990.
Putin said Russians have become keenly aware how important it is for the fatherland and society to be united. He said unity represents dedication and responsibility for their country.