An earthquake measuring 5.6 on the Richter scale has struck off the coast of southern Mexico, 119 kilometers (73.9 miles) from Tres Picos. The quake had a depth of 21.7 kilometers, according to the US Geological Survey (USGS). It comes less than two weeks after Mexico was hit by a destructive 7.1 magnitude quake which killed at least 337 people. In early September, an 8.2 magnitude earthquake struck the country, killing at least 98 people and producing more than 5,400 aftershocks. Mexico sits atop five tectonic plates, the movement of which making it one of the most seismically-active countries in the world.