[Pope Francis delivers a speech at the port of Mytilene where he met local population and threw a wreath of flowers in memory of the migrants died at sea trying to reach Europe, on the Greek island of Lesbos]Three families of Syrian refugees boarded Pope Francis's plane heading back to the Vatican on Saturday after his lightning visit to a Greek island on the frontline of Europe's migrant crisis, a Reuters witness said. "The Pope has desired to make a gesture of welcome regarding refugees, accompanying on his plane to Rome three families of refugees from Syria, 12 people in all, including six children," a statement issued by the Vatican said.