By Philip Pullella and Karolina Tagaris LESBOS, Greece (Reuters) - Pope Francis took three families of Syrian refugees back to Rome on Saturday after visiting the frontline of Europe's migrant crisis at a camp in Greece where migrants wept at his feet, kissed his hand and begged for help. At a sprawling fenced complex on the Aegean island of Lesbos, adults and children broke down in tears before the head of the Roman Catholic church, after their onward journey to Europe was cut short by an EU decision to block a migrant route used by a million people fleeing conflict since early 2015. While borders have now largely been shut for migrants, Francis symbolically took a small group of refugees with him on his aircraft as he left the island after a five-hour visit.