TOKYO, May 20 (Reuters) - A Japanese agency apologised on Wednesday for issuing an erroneous alert for a magnitude 7.6 earthquake, saying the alert for southern Japan had been issued as part of a drill.
"We are looking into what happened," Yoshiro Ota, an official at the Japan Meteorological Agency, told Reuters.
"Usually, when it is a drill, it is flagged as a drill in the alert," he said.
Residents in southern Japan were calling the agency to find out why the alert had been issued. Witnesses in southern Japan contacted by Reuters said they had felt no shaking.
Japanese media did not report on the alert on the website because they had been warned in advance that the agency would conduct a drill, Ota said.
Kyodo news agency reported that the agency had posted an earthquake alert on its website in error.
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.
In October 2004, an earthquake with a magnitude of 6.8 struck the Niigata region in northern Japan, killing 65 people and injuring more than 3,000. (Reporting by Chisa Fujioka)