ISTANBUL (Reuters) – Ecumenical Patriarch Bartholomew, the spiritual head of Eastern Orthodox Christians worldwide, called overnight for the opening of humanitarian corridors in Ukraine where he said “an indescribable human tragedy is unfolding”. Bartholomew, who has previously called for an end to war in Ukraine, said that he hoped this year’s Easter would be “the impetus to open humanitarian corridors, safe passages to truly safe areas for the thousands of people surrounded in Mariupol.” “The same applies to all other regions of Ukraine, where an indescribable human tragedy is unfolding… W…