A powerful earthquake has rocked the Japanese city of Sapporo, the capital of the northern Hokkaido prefecture. The magnitude 6.7 quake struck 112 kilometers south of the city at an approximate depth of 32 kilometers, according to the US geological service (USGS). The earthquake took place around 03:07 (local time) (18:07 GMT). No damage or injuries were immediately reported and no tsunami warning was issued.