Sep 09 (NHK) - Japanese seismological authorities say the northern prefecture of Hokkaido has been jolted by more earthquakes since a major quake struck 3 days ago.
A magnitude-6.7 earthquake hit the region on Thursday. The epicenter was located in Iburi. The highest level of seismic intensity, on the country's scale of 0 to 7, was recorded in the town of Atsuma.
The Japan Meteorological Agency says that more than 140 tremors were felt in areas close to the epicenter before 4 AM on Sunday. It says the jolts are believed to be aftershocks.
The agency is urging people in the affected areas to be careful, as quakes with an intensity of up to 7 may continue to occur until around next Thursday.
Rain is expected in the Iburi region from Sunday afternoon through Monday.
The agency says that the rain could increase the risk of mudslides in areas where quakes have loosened the ground.
