Sri Lanka, May 20 -- A magnitude 5.9 earthquake shook southern Japan on Wednesday, according to the US Geological Survey. The quake occurred at 11:46 a.m. local time (0246GMT) at a depth of 50 kilometers (31 miles). The Disaster Management Division of the Japanese prime minister's office reported that the tremor was felt across parts of southern Japan, with a seismic intensity of lower 5 recorded in Southern Amami in Kagoshima province. Authorities did not issue a tsunami warning, and no immediate damage or injuries were reported.

Japan is one of the most seismically active countries in the world, sitting on the Pacific Ring of Fire. The country has stringent building codes and early warning systems that have significantly reduced casual...