By Natalia Zinets LVIV, Ukraine (Reuters) – Ukraine accused Russia on Wednesday of bombing a children’s hospital in the besieged port of Mariupol during a supposed ceasefire to enable some of the hundreds of thousands of civilians trapped in the city to escape. Russia had said it would hold fire to let civilians flee Mariupol and other besieged cities on Wednesday. But the city council said the hospital had been hit several times. “The destruction is colossal,” it said in an online post. President Volodymr Zelenskiy called it an “atrocity”. “Direct strike of Russian troops at the maternity hos…