Strong quake jolts southern Japan

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TOKYO, July 8 (Reuters) - A strong earthquake with an estimated magnitude of 6.0 jolted southern Japan on Tuesday, a government agency said, but there was no risk of a tsunami.

The focus of the tremor was in the ocean 50 km (31 miles) below the surface off the island of Okinawa, which is around 1,600 km (1,000 miles) southwest of Tokyo, the Japan Meteorological Agency said.

Public broadcaster NHK said there were no immediate reports of injuries or damage and video footage from Naha, the island's capital, showed streets looking normal, with cars on the roads.

Earthquakes are common in Japan, one of the world's most seismically active areas. The country accounts for about 20 percent of the world's earthquakes of magnitude 6 or greater. (Reporting by Masayuki Kitano and Isabel Reynolds)