Cartegena - Pope Francis wrapped up his Colombia trip Sunday by honouring a fellow Jesuit who ministered to African slaves and urging Colombians today to follow his lead in working for a more peaceful future.Francis' visit to Cartagena got off to a rocky start when he bonked his head on his popemobile when it stopped short amid swarms of well-wishers. Francis, who had only a hip-high bar to hold onto, lost his balance and suffered a bruised, black left eye and a cut on his eyebrow that dripped blood onto his white cassock.The cut was quickly bandaged with a butterfly patch and Francis carried on without incident with his programme, sporting a shiner that got increasingly dark as the day wore on.The highlight of the day was a very personal stop for the Jesuit pope: He prayed at the tomb of St Peter Claver, the 17th century missionary who ministered to hundreds of thousands of African slaves who were brought through Cartagena's port during Spanish colonial times to be sold.Francis, known for his own simple and austere style, said Claver was "austere and charitable to the point of heroism".Claver, the self-described "slave of the slaves forever", has been revered by Jesuits, popes and human rights campaigners for centuries for having insisted on recognising the inherent dignity of slaves, treating them as children of God when others considered them mere merchandise to be bought and sold."Be slaves of peace forever," he said in a final appeal at the end of Mass in Cartagena's port.Venezuela Francis had refrained until Sunday from speaking out about the political and humanitarian crisis next door in Venezuela. But in remarks added into his Sunday prayer, Francis called for an end to political violence in Venezuela and protection for the poor who have been most hurt by the crisis.While the appeal was welcomed, many in the crowd were more taken by Francis' mishap on the popemobile and his bruised and bloody eye."This holy blood is staying in Colombia," said Ricardo Morales, a lawyer who lined up outside St Peter Claver's church for a glimpse of the pope.