A powerful earthquake measuring magnitude 6.7 has struck off the coast of the Japanese region of Miyagi, north of Tokyo, prompting the government to issue emergency warnings to people in five prefectures.

The Japanese authorities rated Friday’s earthquake a five on its 1-7 intensity scale, but said there was no immediate risk of a tsunami.

The focus of the 8.22pm (local time) quake was off the coast of Miyagi prefecture.

The US Geological Survey said the earthquake’s epicentre was 50km east of the town of city of Ofunato and at a relatively large depth of around 43km.

The USGS revised the magnitude of the quake from 6.6 to 6.7.

The earthquake also registered a lower 5 on the Japanese scale in the cities of Tome, Osaki and Ishinomaki in Miyagi Prefecture, according to reports in the Japan Times. The new site added that areas of Miyagi and Iwate prefectures also saw the quake register a 4 on the Japanese scale.

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