Tokyo: The death toll from earthquakes in southern Japan has risen to 41 after a magnitude 7.3 quake struck just 24 hours after a smaller one devastated the area.

The latest quake occurred in southern Japan early on Saturday, at a depth of 12 kilometres, causing strong vibrations across the island with a population of 13 million people. Almost 2,000 people were injured in the most recent quake, according to Japanese broadcaster NHK.

People still reeling from a magnitude 6.5 quake on Thursday poured onto the streets after the Saturday quake struck at 1.25 am.

A landslide caused by the earthquake in Minamiaso, Kumamoto prefecture, in southern Japan on Saturday. Photo: AP

It was followed by a series of aftershocks that were almost at the the top of Japan's intensity scale. The shaking was most powerful close to Mt. Aso, an active volcano and popular tourist site. A small eruption was spotted at Mt. Aso after the quake, NHK reported.

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Television footage showed houses flattened and landslides that had swallowed up roads and railway lines in the village of Minamiaso. Authorities warned of further damage, with strong rain expected to worsen conditions later Saturday. A tsunami warning was briefly issued after the earthquake, but was lifted less than an hour later.

About 170,000 people have been advised to evacuate, the Kumamoto government said.

A resident in front of a damaged house in Mashiki, Kumamoto prefecture, in southern Japan on Saturday. Photo: AP

Prime Minister Shinzo Abe has mobilized a team of about 20,000 rescuers comprising self-defense forces, police and firefighters, according to a statement from his office. Abe called for heightened relief efforts before the weather turned unfavorable later Saturday.

There was no impact from the earthquakes on nearby nuclear plants, with Kyushu Electric Power Co.'s Sendai facility, which houses the only operating reactors in Japan, continuing to run. Environment Minister Tamayo Marukawa said the plant doesn't need to be shut down at this point.

An official from the Japan Meteorological Agency speaking on NHK said the initial magnitude 6.4-level event that shook Kumamoto late Thursday night was a foreshock to the overnight earthquake.

A shopping arcade destroyed by the earthquake in Kumamoto city, southern Japan on Saturday. Photo: AP

Kumamoto airport has been closed after suffering damage, with all 74 domestic and international flights canceled on Saturday.

More than 200,000 homes were without power, according to Kyushu Electric Power.

Authorities warned of damage over a wide area, as reports came in of scores of people trapped in collapsed buildings, fires and power outages.

Police officers carry a dead body past the relatives after the body was found at a site collapsed by an earthquake in Mashiki, Kumamoto prefecture, on Saturday. Photo: AP

Residents living near a dam were told to leave because of fears it might crumble, broadcaster NHK said.

A fire erupted in a what appeared to be an apartment building in Yatsushiro city, while some people were trapped in a nursing home in the town of Mashiki, according to NHK.

Chief Cabinet Secretary Yoshihide Suga said nearly 80 people were believed trapped or buried in rubble. Extra troops would be sent to help, with up to 15,000 due on Saturday, as well as more police, firefighters and medics, he said. "We are making every effort to respond," Mr Suga said.

Houses are buried in a landslide caused by an earthquake in Minamiaso, Kumamoto prefecture, on Saturday. Photo: AP

Troops fanned out to search ruined houses as dawn broke.

The epicentre of the quake was near the city of Kumamoto and measured at a shallow depth of 10 km, the US Geological Survey said. Almost 200,000 households were without power.

The region's transport network suffered considerable damage with one tunnel caved in, a highway bridge damaged, roads blocked by landslips and train services halted, media reported. Kumamoto airport was also closed.

Bank of Japan Governor Haruhiko Kuroda said it was too early to assess the economic impact and bank operations in Kumamoto were normal.

"We'll closely monitor the effect of the earthquake and take appropriate action, working closely with relevant authorities," Kuroda said in Washington after a G20 finance leaders' meeting.

Much of the area around Kumamoto and a few sizeable towns is rural. Television footage showed many frightened people wrapped in blankets sitting outside their homes while others camped out in rice fields.

The earthquake on Thursday evening in the same region was of 6.4 magnitude and experts said the tectonic events could be linked.

"We would not be surprised to see more earthquakes of this size," said John Bellini, a geophysicist with the U.S. Geological Survey.

A magnitude 9 quake in March 2011 north of Tokyo touched off a massive tsunami and nuclear meltdowns at Fukushima. Nearly 20,000 people were killed in the tsunami.

Japan is on the seismically active "ring of fire" around the Pacific Ocean and has building codes aimed at helping structures withstand earthquakes.

Factories in the area operated by manufacturers including Honda Motor and Sony Corp halted production after Thursday's tremor but no major damage was reported.

The 2011 quake temporarily crippled part of Japan's auto supply chain, but some companies have since adjusted the industry's "Just in Time" production philosophy in a bid to limit any repeat of the disruption.

Reuters, McClatchy, AP