A 6.4 magnitude earthquake struck just off Peru's southern coast today, the US Geological Survey said, with no immediate reports of injuries or damage. The quake hit at approximately 9:05 pm local time with a depth of 44 kilometers. It occurred some 220 kilometers west of Arequipa, Peru's second most populous city. Though there was no initial evidence of damage the tremor provoked alarm among Peruvians, with the Mayor of the southern town of Caraveli saying residents there had taken to the streets. "The tremor has been very strong here in Caraveli," Mayor Santiago Neyra said. "It has generated fear in the population." Social media users suggested the quake was felt as far south as the country's Chilean border. Peru lies on the so-called "Ring of Fire" - an arc of fault lines that circles the Pacific Basin and is prone to frequent earthquakes and volcanic eruptions. The South American country records about 200 earthquakes a year, most of them going unnoticed by the public. The last major earthquake to shake Peru hit in August 2007, killing 595 people.