A magnitude 5.9 earthquake struck the Sumbawa region of Indonesia, according to the GFZ German Research Centre for Geosciences (a Potsdam-based institute that monitors seismic activity worldwide). The source provided no details on casualties or damage. Sumbawa (an island in the Lesser Sunda chain of eastern Indonesia) lies on the Pacific 'Ring of Fire', making the country prone to frequent quakes and volcanic activity.