Evacuation of the besieged Ukrainian city of Mariupol is underway after multiple prior failures to secure a ceasefire that would allow for the safe operation of a humanitarian corridor, according to an adviser to the city’s mayor. Petro Andrushenko, an adviser to the mayor of Mariupol, said in a Monday post on Facebook that, as of 1 p.m. local time, a ceasefire was being observed along a corridor leading out of the city towards Zaporizhia. “Let’s help everyone out! Call, write to everyone whom you reach!” he wrote, while cautioning that local Ukrainian authorities are unable to officially guarantee safety down the corridor. Still, he said that the evacuation route was operational and that residents are able to leave using their own modes of transport. He said around 160 vehicles had already managed to depart Mariupol via the corridor. The Mariupol City Council was cited by Interfax Ukraine as saying that …