6.8 quake off Japan prompts brief tsunami warning

A powerful 6.8-magnitude earthquake struck Friday off Japan’s northeast coast, prompting officials to issue a brief tsunami advisory warning for two coastal prefectures already devastated by the March 11 temblor and tsunami.

No damage or injuries have been reported, and the tsunami advisory was lifted after no waves were sighted. Still, in the moments after the quake, some highways were closed and some bullet trains halted in a nation still skittish over the March disaster.

Tokyo Electric Power Co., the utility that runs the ailing Fukushima Daichi plant, said no danger signals had been detected from monitoring posts at the facility, which was damaged in the March disaster.

The tsunami warning was issued for the Fukushima and Miyagi prefectures, where 25,000 residents were killed or went missing. More than 80,000 people near the Fukushima Daichi plant were evacuated after the site sustained meltdowns inside several reactors.

Japanese Prime Minister Naoto Kan is slated to step down this month under fire from critics for his government’s mishandling of the crisis. Months after the springtime disaster, many Japanese still languish in emergency shelters and many others remain without work.

Friday’s temblor struck at 2:36 p.m., off the coast of the Fukushima prefecture, about 12 miles below the earth’s surface, said officials from the Japan Meteorological Agency.

john.glionna@latimes.com