Workers battling to control the stricken nuclear plant on Japan's northeast coast were ordered to evacuate after a 7.4 magnitude quake hit the area and a local tsunami warning was issued, operator TEPCO said Thursday.

"After the earthquake and the tsunami warning, all the workers evacuated to a safe area. The company confirmed all the workers have cleared the plant safely," a spokesman for Tokyo Electric Power said.

"We have no information immediatelly indicating any abnornality at Fukushima Daiichi plant," a spokesman told a press conference.

"We will release new information as it becomes available," he said.

Workers have been grappling to secure damaged reactors at the plant, which was badly hit by the massive tsunami that hit Japan's northeast on March 11.

Cooling systems were knocked out, leaving the temperature of the nuclear cores to rise and setting off a scramble to prevent a meltdown.