United Nations warns Ukraine is facing a growing humanitarian crisis, with reports that tens of thousands of Ukrainians are without food, water and heat during the Russian military's deadly assault on the country. The big picture: Over 2 million refugees have fled Ukraine since the Putin-ordered invasion began two weeks ago. Many more remain trapped in the country. Ukrainian officials have accused Russian forces of shelling humanitarian corridors, despite Kremlin pledges to hold fire and enable civilians to leave. Firefighters try to extinguish a blaze after a chemical warehouse was hit by Russian shelling near the town of Kalynivka, southwest of Kyiv, on March 8. Photo: Chris McGrath/Getty Images Civilians flee Sumy after Russia announced a temporary ceasefire for the city in northeastern Ukraine on March 8. Photo: Ukrainian Presidency/Handout/Anadolu Agency via Getty Images A man walks between houses destroyed during air strikes on the central Ukranian city of Bila Tserkva on March 8. Photo: Aris Messinislvi/AFP via Getty Images Evacuees from eastern Ukraine wait for a train at the railway station in the western Ukrainian city of Lviv on March 8. Photo: Yuriy Dyachyshyn/AFP via Getty Images A man injured during a Russian military attack receives treatment in the central hospital of Mykolaiv, some 60 miles from Odessa, western Ukraine, on March 8. Photo: Bulent Kilic/AFP via Getty Images An elderly woman is assisted during Irpin evacuations on March 8. Photo: Andriy Dubchak/DIA Images via Getty Images Ukrainians attend first aid training at an underground room in Lviv on March 8. Photo: Alejandro Martinez/Anadolu Agency via Getty Images An apartment building damaged on March 8 after shelling the day before in Kharkiv, northeastern Ukraine. Photo: Sergey Bobok/AFP via Getty Images Volunteers sort through supplies from aid donations in Dnipro, central Ukraine, as Russian military attacks continue. Photo: Andrea Carrubba/Anadolu Agency via Getty Images A damaged civil settlement after a shelling in the pro-Russian separatists-controlled Donetsk in eastern Ukraine on March 8. Photo: Leon Klein/Anadolu Agency via Getty Images A woman and her dog sitting on a makeshift bed in a underground metro station used as a bomb shelter in Kyiv on March 8. Photo: Dimitar Dilkoff/STF/AFP via Getty Images A man buys food in a damaged store in Ukraine's second-biggest city of Kharkiv on March 8. Photo: Sergey Bobok/AFP via Getty Images A woman carries her dog during Irpin evacuations on March 8. Photo: Sergei Supinsky/AFP via Getty Images Volunteers filling the bags with sand on local beaches for the protection of civilian and military facilities in Odessa, southern Ukraine, on March 8. Photo: Nina Liashonok/Ukrinform/NurPhoto via Getty Images Rozalia Choba, 98, who spent 10 years in Siberia as a political prisoner, with an old photo of herself, in the village of Solonka, near Lviv on March 8. "If the Russian tank comes I would tell him 'Go to your homeland, I'll give you more bread on the way, just go back," she told AFP. Photo: Clara Marchaud/AFP via Getty Images Ukrainians are assisted during Irpin evacuations. Photo: Andriy Dubchak/dia images via Getty Images People heading to a Kyiv train station to flee the city after Russia announced a temporary ceasefire on March 8. Photo: Emin Sansar/Anadolu Agency via Getty Images Buses preparing to leave Zaporizhzhya, southeastern Ukraine, for Mariupol to deliver humanitarian aid and evacuate people on March 6, after Russian officials said they'd open a humanitarian corridor. The International Committee of the Red Cross said later this attempt failed, citing concerns about the ceasefire agreement. Photo: Dmytro Smolyenko/Ukrinform/NurPhoto via Getty Images Go deeper: The latest on the Russia-Ukraine crisis
Editor's note: This article has been updated with more images.