Ukrainian officials have accused Russian forces of attacking humanitarian convoys attempting to bring food and other essentials to the port city of 430,000 people.
Mariupol is strategically important for Russia because it would unite separatist forces in eastern Ukraine with Russian troops in Crimea - leaving Ukrainian troops there isolated or encircled.
Tanks have also been seen firing on a nine-storey apartment building, while a group of hospital workers came under sniper fire on Friday.Huge damage in Mariupol after blasts• 12,729 people were evacuated through humanitarian corridors in other Ukrainian cities on Saturday, Zelenskyy says •"We did not detect a willingness on Putin's part to end the war," a French presidential official says• Britons who host Ukrainian refugees will receive £350 a month as a"thank you" from the UK governmentIn a statement filmed on Saturday night, Mr Zelenskyy claimed that Russian"invaders" in Kherson are trying to establish a breakaway region.