An earthquake of magnitude 6.5 occurred on Monday in the Amazonian state of Acre in Brazil's North Region, but had virtually no effect on the surface and caused no damage or casualties, the Seismological Observatory of Brasilia University (Obsis-UnB) told Xinhua.

The tremor happened at 11:18 local time (1618 GMT), measuring 6. 5 on the Richter scale and located at a depth of 580.5 kilometers. The epicenter is some 127 km from the city of Cruzeiro do Sul, where no damage was reported.

According to Obsis-UnB, the state of Acre is located in a place where the Nazca Plate meets the South American Plate, resulting in frequent earthquakes.

Though often strong in magnitude, the earthquakes usually occur in great depths and are hardly felt on the surface, explained Kate Tome Algarte, a geologist from the UnB seismological center.

The Fire Department of Cruzeiro do Sul told local media that nothing was perceived at any point in the city.