An earthquake of at least 6.6 magnitude has shaken Bolivia, causing no damage or injuries but driving people out of office buildings as far away as Brasilia and Sao Paulo in neighbouring Brazil, officials say.
In Bolivia, the quake shook tall buildings, but no damage or injuries had been reported about two hours after the initial shake early on Monday, according to the South American nation's San Calixto Seismological Observatory.
The observatory put the quake's magnitude at 6.6 but the US Geological Survey said it was 6.8.
The tremor, its epicentre 557km deep, rocked an area approximately 300km southeast of Sucre, a Bolivian city in the country's southern highlands, the United States Geological Survey (USGS) said.
In Brazil, the tremor shook high rises as far away as Sao Paulo and Brasilia, causing minor panic in a country where earthquakes are infrequent.
Television images showed workers leaving office buildings on Avenida Paulista, a central boulevard in Sao Paulo, about 2000km from the quake's epicentre.
In Brasilia, local broadcaster GloboNews showed dozens of people evacuating buildings in the city's south side commercial district, some standing in the rain with umbrellas.
The USGS initially put the quake at magnitude 6.9 and a depth of around 554km, but later revised its reading.