A magnitude-6.1 earthquake struck northern Japan early Monday, the U.S. Geological Survey said, but there were no immediate reports of injuries or damage.
According to the USGS, the quake struck at a depth of 81 kilometers (50 mi) 18 kilometers (11 mi) west of the small city of Sarabetsu in Hokkaido.
Last Monday, an earthquake of 7.7 magnitude occurred in the northern region. Japan Issued a short-term tsunami warning and advised a slightly higher risk of possible megaquake for its coastal areas.
