Aparecida, July 24 - An estimated 200,000 Catholics on Wednesday morning were waiting for the arrival of Pope Francis at the shrine of the Madonna of Aparecida, venerated as the patroness of Brazil. The pontiff left his residence in Rio de Janeiro on the third day of his visit to Brazil for events related to World Youth Day and travelled to the airport where he will board a plane to travel to San Jose' dos Campos. He will then continue the trip to Aparecida, some 260 km from Rio, by helicopter. He did not take a helicopter for the whole trip as originally planned due to poor weather conditions. Security around the shrine will be tight and potential protests in the area ''will be immediately halted'', police said. Local media reports said three groups of homeless based in Sao Paulo, about 170 km from Aparecida, are planning a rally on Wednesday morning to coincide with the pontiff's visit. On Wednesday afternoon the pope is scheduled to return to Rio to visit a hospital managed by Franciscans and meet youths taking part in a drug rehabilitation programme.