Monday's major earthquake in western Japan left 4 people dead and more than 370 injured.

The Meteorological Agency is warning it's possible another big earthquake could hit in the coming days.

Agency's official says "Frequent seismic activity is continuing in the northern part of Osaka Prefecture.

Strong tremors could have raised the risk of landslides or building collapse. People in such areas are advised to watch out for further seismic activity and rain."

The earthquake struck before 8 AM in northern Osaka and measured 6.1 in magnitude.

On Japan's seismic intensity scale of zero to seven, it's categorized as a six-minus.

9-year-old Rina Miyake was killed when a wall collapsed while she was on her way to school.

80-year-old Minoru Yasui was also hit by a falling wall in a different area. He was on his way to do volunteer work for a local school.

85-year-old Motochika Goto was killed after a bookshelf fell on him. Many of the injured have been taken to hospital with the biggest number of injuries reported in the prefecture of Osaka.

Authorities are also dealing with damage. Firefighters have put out three house fires in northern Osaka.

Pipes have cracked underneath some roads and ceiling tiles fell in city halls in Osaka, Hyogo and Nara Prefectures as well as at the terminal building of Osaka airport.

Around 1,300 people have fled to evacuation centers set up across Osaka. 100,000 homes are without gas and water outages are being reported in the northern half of Osaka.

Shinkansen bullet train services in the area were suspended for hours for safety checks.

All the service resumed in the afternoon, but there were numerous cancellations and delays.

Local trains have also been affected, stranding thousands of passengers.

Japan's nuclear regulator says no problems have been found with reactors in Fukui Prefecture.

They are located to the north of the quake's epicenter.