(CNN) – A strong earthquake shook the Ogasawara Islands south of mainland Japan Saturday. The United States Geological Survey said the quake measured 6.6 in magnitude. The quake was centered in the Pacific Ocean, about 885 kilometers (550 miles) south of Shizouka, Japan, to the west of the Ogasawara Islands, which are also known as the Bonin Islands. The earthquake's epicenter was 454 kilometers (282 miles) deep. There are no reports of damage or injuries.