Local media reports say half a dozen manholes have exploded in Rio de Janeiro's showcase Copacabana beach neighbourhood.
G1 Internet portal says no injuries were reported in the explosions, caused when accumulated underground gas tossed the heavy metal lids several metres into the air.
The report quotes Joao Barros, a doorman who witnessed yesterday's explosions, as saying they "sounded like dynamite." Barros said smoke billowed out of some manholes.
Firefighters and technicians from Rio's Light electric utility have cordoned off the area. The G1 report cites utility officials saying there's a short circuit in the area.
The phenomenon isn't a new in Rio, which will host next year's World Cup and the 2016 Olympics.
In 2010, an American couple was seriously burned in a similar blast.
