Japan issues tsunami alert after 6.5 magnitude earthquake hits its west coast

Japan on Tuesday issued a tsunami alert after a powerful 6.5 magnitude earthquake hit Niigata and Yamagata prefectures located in the west coast of the largest Japanese island, Honshu.

"A marine threat is present. Get out of the water and leave coastal regions immediately," the advisory read.

"Due to the risk of ongoing strong currents, do not enter the sea or approach coastal regions until the advisory is lifted," it added.

The quake, which occurred at around 10:22 p.m. (local time), prompted the Meteorological Agency to issue tsunami advisories for coastal areas of Yamagata and Niigata prefectures and the Noto area in Ishikawa Prefecture. The agency estimated the possible tsunami's height to be as much as 1 meter, The Japan Times reported.

The agency also stated that some fluctuation of the sea surface is expected but it's unlikely to cause major damage.

Tohoku Electric Power Company was quoted as saying that nearly 5,000 households were experiencing a power outage in Yamagata Prefecture while 3,200 were without power in Niigata as of 11:00 p.m. (local time).

In addition, Tokyo Electric Power Company Holdings Inc. told The Japan Times that it found no irregularities at all seven reactors at the Kashiwazaki Kariwa nuclear plant in Niigata. However, the reactors are currently closed down.

East Japan Railway Company was also quoted as saying that it has suspended the operation of the Joetsu and Tohoku Shinkansen lines. The bullet train services in the region were suspended immediately after the jolt.

The Japanese government has set up a task force to gather information on the matter.

According to preliminary reports, the epicentre of the quake was located at a depth of some 10 kilometres below the ground, Russia Today reported.

So far, however, no information on the potential damage and injuries has emerged, only a 'slight' rise in water levels has been observed.