A powerful tremor that struck Japan on Monday, one of hundreds of aftershocks stemming from the massive earthquake-tsunami that hit a month ago, killed three people, emergency services said Tuesday.

The three victims were found in debris from a landslide that destroyed houses in Iwaki city in Fukushima prefecture after the 6.6 magnitude quake on Monday evening.

The news came as Japan was hit by yet another powerful quake, which had an epicentre close to Iwaki and was measured at 6.0 magnitude by the US Geological Survey.

A spokesman for the Fire and Disaster Management Agency said firefighters had pulled two bodies from one of the houses, while rescuing four people from another.

"One of the rescued individuals died later in hospital," the spokesman said, adding that three people were badly injured in the landslide.

Jiji Press, citing police and fire department authorities, said Monday a 46-year-old man in Ryugasaki in Ibaraki prefecture had died after hitting his head following the quake.

Japan is still reeling from a 9.0 magnitude undersea quake and the huge tsunami it generated on March 11.

More than 13,000 people are known to have died with over 14,000 still unaccounted for in the country's worst calamity since World War II.

Hundreds of kilometres (miles) of coast were battered by the wave, which destroyed whole towns in the northeast and sparked an atomic emergency at the Fukushima Daiichi nuclear plant.

earlier related report
Powerful quake rocks Tokyo
Tokyo (AFP) April 12, 2011 - A strong offshore earthquake rocked Tokyo on Tuesday, swaying buildings in the Japanese capital and stopping subway services.

The US Geological Agency put the magnitude at 6.4, at a depth of 13.1 kilometres (8.1 miles), 77 kilometres east of Tokyo. The Japan Meteorological Agency had measured it at 6.3.

The quake hit at 8:08 am (2308 GMT Monday) off the coast of Chiba prefecture, just east of the capital. Japanese experts said there was no chance of a tsunami.

There were no immediate reports of fresh damage, including at the crippled Fukushima Daiichi nuclear power plant, which has been releasing dangerous radioactive materials since it was damaged by the March 11 tsunami, Tokyo Electric Power Co. said.

Subway services in Tokyo temporarily stopped, but resumed operations shortly afterwards.

The runways of Narita international airport in the prefecture were temporarily closed for checks but had since reopened, Kyodo News said.

The limited shinkansen bullet train services running to the northern region since the March 11 earthquake and tsunami were briefly interrupted.

The latest quake was an aftershock "in a broad sense of the word" of the 9.0-magnitude quake of March 11 that killed more than 13,000 and left over 13,500 missing, Koshun Yamaoka, professor at Nagoya University, told public broadcaster NHK.

"We have to be aware of aftershocks, particularly in the first and second months after the original quake," he said.

Japan has experienced more than 400 aftershocks stronger than magnitude 5.0 since March 11.