Brasilia, February 5 (RHC) -- A flaw in the national distribution system cut off electricity supplies to more than 1 million people in Brazil on Tuesday

The blackout affected part areas in each of the some 10 southern, southeastern and mid-western states, local media said. Some neighborhood in Sao Paulo had power, while others did not, it added.

In Brazil's two largest cities, Rio de Janeiro and Sao Paulo, the blackout knocked out traffic lights, causing traffic problems as well.

The blackout was blamed on disturbances in the national electric system, which triggered an automatic shut-off response to some distributors, local media said.

The National Electric Power System Operator, or ONS, the government agency that controls the network, reportedly asked regional distribution companies to turn off energy distribution in some regions to prevent an even bigger blackout.