ANKARA 

A strong earthquake struck northern Japan on Saturday, according to the US Geological Survey (USGS), with no immediate reports of damage.

The magnitude 6.1 quake hit near the city of Kushiro on the island of Hokkaido at approximately 5.37 pm local time (0837GMT), the USGS reported.

The tremor occurred at a depth of 20 kilometers (12 miles), the agency said.

As of the time of publication, Japanese authorities had not released any official statements regarding casualties or structural damage. No tsunami warning was issued following the earthquake.