MOSCOW, March 30 (RIA Novosti) - Municipal authorities in Rio de Janeiro have decided to build cement walls to stop the growth of favelas, or slums, national media reported on Monday.

Work was begun on a cement barrier on Saturday in the favela of Dona Martha, located at the foot of Corcovado Mountain, from which the famous Christ the Redeemer statue towers over the former Brazilian capital.

This is reported to be the first section of 11 kilometers (6.8 miles) of walls to be built by the end of 2009 to keep the slums, infamous for their criminal groups and drug pushers, from expanding. The walls are three meters high and will cross through 11 outlying quarters of the city, at a cost of some $17.6 million.

The project managers believe that the walls will help in the fight against violence and illegal drug trafficking in Rio de Janeiro, as well as curb "inter-slum" fighting from trickling into the city.

Brazilian President Luiz Inacio Lula da Silva and several human rights organizations have expressed their concern over the municipal authorities' decision to build the walls, saying that they could intensify and worsen the country's massive gap in living standards.

Brazil, where some 35% of the population lives beneath the poverty line, is one of the most economically unequal countries in the world. In 2004, it was estimated that 19% of Rio's population lived in favelas.