Thousands of residents have been asked to evacuate the area surrounding a northeast Japan nuclear plant a "quake spawned tsunami" slammed the country's coastline. The danger zone was cleared out after the reactor's cooling system failed.

Japanese Prime Minister Naoto Kan has left Tokyo by helicopter for quake-hit northeastern Japan. Kan told reporters just before leaving that he is planning to land near the Fukushima No. 1 nuclear power plant.

The Fukushima Number One Power Plant is in the city of Onahama, located about 270 kilometers northeast of Tokyo.

Authorities have ordered thousands of residents to move at least three kilometers away from the facility.

He said, "We have asked the people in Fukushima, living within 3 to 10 kilometers, to evacuate as a precaution against a nuclear plant explosion."

The earthquake triggered a power outage and, when a back-up generator also failed, the system was unable to supply water to cool the reactor.

The core remains inhumanely hot, even after a shutdown. Experts say if the disruption persists, radiation could eventually leak out into the environment, and, in the worst case, cause a severe meltdown.

The Chief Cabinet Secretary said the site was not leaking radiation as of Friday evening.

Japan's nuclear safety agency adds that the evacuation, ordered by local officials in Fukushima, affects at least 2,800 people.

The move comes after the government declared a State of Emergency at the location.

The facility sits just south of worst-hit Miyagi Prefecture, where a major fire broke out at another power plant.