TOKYO, April 4 (Reuters) - An earthquake with a preliminary magnitude of 5.0 shook Tokyo buildings on Friday, but there were no immediate reports of injuries or damage.

The earthquake registered four out of seven on a Japanese scale of quake intensity, a government agency said, a level that suggests hanging objects would swing considerably but there was unlikely to be serious damage.

The agency said it saw no tsunami threat from the quake.

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.

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