Eastern Japan, where the crippled Fukushima nuclear power plant is located, has been shaken anew by a 5.5 magnitude earthquake on Sunday morning. Tokyo Electric Power Co (Tepco), operator of the embattled power plant, said the facility has suffered no abnormalities so far.

"We have so far seen no abnormalities in monitoring post figures around the plants or in other parameters," a Tokyo Electric spokesman was quoted by Reuters. Fukushima is located 220 km (130 miles) northeast of Tokyo.

The quake, according to the U.S. Geological Survey, struck 7:37am (local time) at a depth of 59 km in Ibaraki prefecture, north of Japan's capital.

The temblor lasted 30 seconds, rocking buildings in Tokyo. Many people reported having felt it.

Public broadcaster NHK reported Tohoku Shinkansen bullet trains connecting Tokyo with northern Japan temporarily suspended their operations for maintenance inspection but quickly resumed normal operations. Tokyo's two international airports continued to operate normally.

Crippled Fukushima power plant has hogged the global limelight ever since it was barraged by a towering tsunami in March 2011, spurred by a tremendous 9.0-magnitude sub-sea earthquake. The temblor killed more than 18,000 people.

The huge waves toppled the nuclear plant's cooling systems, forcing reactors to meltdown. The disaster forced tens of thousands of people to flee the radiation-stricken area.

For two years now, Fukushima has leaked gallons of highly radioactive contaminated water into the Pacific Ocean, which experts and environmentalists believed were more than what Tepco has been saying.

Just in October 2013, miscalculations by some of the plant's workers had leaked 114 gallons, which had radiation readings 6,700 times higher or as high as 200,000 becquerels per liter. The legal limit is 30 becquerels per liter.

Tepco in August 2013 had received full government backing to clean up the crippled plant.

But experts and environmentalists continue to be wary.

"If an incompetent doctor killed numerous patients doing routine surgery - and then lied and tried to cover it up - would you let him perform brain surgery on a VIP such as the president?" an article published by Global Research said.