A hand grenade is seen tied to the bars of a window Wednesday in Mariupol, Ukraine, as the country’s eastern Donbas region looks set to become the new focal point of Russia’s assault. Photo: Leon Klein/IC Photo

A Russian soldier inspects a destroyed theater Tuesday in Mariupol. An airstrike that hit the theatre on March 16 left at least 300 dead, according to Ukrainian authorities. Photo: Sergei Ilnitsky/IC Photo

Russian-backed Ukrainian separatists load a rocket-propelled grenade launcher on an infantry combat vehicle Tuesday in Mariupol. Photo: Alexander Ermochenko/IC Photo

Russian-backed Ukrainian separatists load ammunition Tuesday into an armored personnel carrier in Mariupol. Photo: Alexander Ermochenko/IC Photo

Russian soldiers walk through the town of Popasna in the Luhansk region Monday. Photo: Alexander Reka/VCG

A photo taken during a Russian military-organized trip to Luhansk shows Russian soldiers guarding the entrance to a power station in Shchastia on Wednesday. Photo: Sergei Ilnitsky/IC Photo

Ukrainian soldiers prepare to fight on the frontline in Donbas on Tuesday. Photo: Diego Herrera Carcedo/VCG

Ukrainian soldiers ready a position on the frontline in Donbas on Monday. Photo: Diego Herrera Carcedo/VCG

A Ukraine soldier jumps onto a tank on the frontline Tuesday. Photo: Diego Herrera Carcedo/VCG

Ukrainian artillery fires on the Donbas frontline Tuesday. Photo: Diego Herrera Carcedo/VCG