Tsunami reaches Japan; Tonga volcanic eruption felt around the world

A weather agency official told a televised, midnight news conference that the agency had detected a tidal change higher than one metre after 11 pm.

The agency didn't immediately classify it as tsunami. However, it decided to activate the public tsunami warning systems to urge the evacuation of Amami residents.

"We don't know at this point whether this is tsunami, but a strong tidal change has been observed, so we're urging residents to respond," the official told the press conference.