Japan issues tsunami alert after 7.4 magnitude earthquake

The Japan Meteorological Agency (JMA) on Monday issued a tsunami warning along the western coastal regions of Ishikawa, Niigata and Toyama prefectures.

The agency said the Ishikawa prefecture, along the Sea of Japan, was hit by a series of quakes measuring a preliminary magnitude of 7.4.

It issued a major tsunami warning for Ishikawa, while the rest of the northwestern coast of the main island of Honshu was issued lower-level tsunami warnings or advisories.

Public broadcaster NHK warned torrents of water could reach as high as 5 meters (16.5 feet).

NHK reported that smaller tsunami waves were already confirmed to have reached the coastline. 

The Japanese government said no abnormalities were reported at the nuclear plant in the area and nearby stations. A news conference was planned for 0910 UTC.

What do we know about the earthquake?

The Noto region, on the Sea of Japan side of Honshu, saw a rapid succession of earthquakes, starting with a 5.7 magnitude tremor at around 4:06 p.m. local time (0704 UTC).

A 7.6-magnitude quake hit just four minutes later and was followed by a series of weaker tremors for around half an hour. 

According to media reports, buildings swayed in the area around the capital, Tokyo, on the central coast of Honshu. 

Broadcasters switched to special programming and were making urgent appeals for residents to leave. 

"We realize your home and your belongings are all precious to you, but your lives are important above everything else. Run to the highest ground possible," a presenter on broadcaster NHK told viewers.