An earthquake measuring 5.1 magnitude on the Richter scale struck off El Salvador on Sunday.The US Geological Survey (USGS) said that the earthquake occurred 34 km from Mizata beach in La Libertad Province, at a depth of 75.3 km.There have been no reports of casualties or material damage due to the earthquake so far.In 2001, a devastating 7.6-magnitude earthquake struck El Salvador, killing hundreds, and injuring and displacing thousands.Source: Qatar News Agency