A magnitude 5.7 earthquake rocked northern Japan (search) late Thursday, weeks after a powerful tremor killed 39 people and injured thousands more. There were no immediate reports of injuries.

The quake, which shook the country's northernmost main island of Hokkaido (search) at 11:03 p.m., was centered 37 miles underground, the Meteorological Agency said.

The quake was about 500 miles north of last month's magnitude 6.8 earthquake that struck rural Niigata prefecture (search).

Earlier Thursday, a magnitude 5.2 temblor struck a rural part of Niigata prefecture, about 160 miles north of Tokyo.

A magnitude 5 earthquake can cause considerable damage.