Violent protests have greeted President George Bush's visit to Brazil.Riot police fired tear gas and beat some protesters with batons after more than 6,000 people held a march through the financial district.In the southern Brazilian city of Porto Alegre, more than 500 people yelled "Get Out, Imperialist!" as they marched through the city and burned an effigy of Bush.The President touched down in Sao Paulo for the first stop on their five-country tour of Latin America to promote democracy, increased trade and cooperation on alternative fuels.Bush and Brazilian President Luiz Inacio Lula de Silva are expected to announce an "ethanol alliance" to promote its use in South and central American countries.The president and his advisers also hoped his visit would offset the growing influence of leftist leaders, such as Venezuela's Hugo Chavez.In addition to Brazil, Uruguay and Colombia, Bush is also visiting Guatemala and Mexico.© Independent Television News Limited 2007. All rights reserved.