The US agency said the quake hit at a depth of 609 kilometers (380 miles) on Peru's eastern frontier with Brazil. Jorge Chavez, the civil defense chief, said the depth of the quake had caused its force to dissipate, blunting its impact on the surface.
"The depth has made it so there is no surface damage," he said on RPP radio. The earthquake hit shortly after 0900 GMT, about 140 kilometers west of the Peruvian town of Iberia, the USGS said.