The Japan Meteorological Agency early Thursday morning issued an early warning for an earthquake that was expected to hit Tokyo and other neighboring areas.
However, no quake vibrations measuring shindo 1 or higher on the Japanese seismic intensity scale were observed.
"We overestimated the magnitude at 7.3 and erroneously located the focus at a point south of the Boso Peninsula, which is totally different from the actual one," said Takashi Kato, director of the agency's Earthquake and Tsunami Observation Division.
"We apologize for causing such a disturbance," he said at a news conference.
