Brazil's President Dilma Rousseff Thursday denied that a massive power blackout happening earlier this week was caused by lightning.
The blackout hit the country on Tuesday, affecting more than 1 million people across 13 states and the Federal District.
Earlier on Thursday, the National Electric Power System Operator (ONS) said it might be caused by lightning.
In a statement released in the late afternoon, Rousseff, who served as Mines and Energy minister under the previous administration, said Brazil could not have an electricity network that was vulnerable to lightning.
She said Brazil's energy distribution system was designed to be lightning-proof with a giant network of lightning rods since the country has one of the highest incidence of lightning in the world.
"If lightning really was responsible for the blackout, then the ONS should investigate whether the energy operators are giving adequate maintenance to their lightning-rod network," said the statement, which was read by Press Secretary Thomas Traumann.
However, according to the ONS, the government agency that controls the network, no human or maintenance flaws caused the blackout.
Authorities also denied that the blackout was caused by elevated electricity consumption in Brazil as a result of a recent heat wave, though just three minutes before the blackout, the southern region had registered record-high energy consumption.
A report that explains the cause of the incident is expected to be ready in two weeks.