>> reporter: in southern ukraine they are trying to flee the city cut off from power, water and heat. a second attempt for safe evacuation corridors breaking down. the red cross tweeting its attempt to start evacuating an estimated 200,000 people failed. ukraine accusing russia of using a humanitarian seize fire as a trick to kill more civilians. >> seize fire took place only for 30 minutes. after that, russian troops continue shelling of mariupol. we face war crimes hour by hour, second by second. >> reporter: russian president volodymyr zelenskyy warns russia plans to bomb odessa with zelenskyy's life increasingly under threat, western officials tell cnn talks are underway about how to support a ukrainian government in exile. but zelenskyy has rejected any thought of leaving kyiv and instead, focussing on boosting the resistance against russia.