Scores trapped as Japan quakes toll hits 32

Homes, roads and railway lines were swept away when huge hillsides collapsed, as thousands of tonnes of mud was dislodged by the thunderous seismic tremors.

Buildings were reduced to rubble, including a university dormitory and apartment complexes, with dozens of people unaccounted for over a wide area.

"We are aware of multiple locations where people have been buried alive," chief cabinet secretary Yoshihide Suga told a press conference.

"Police, firefighters and Self Defense Force personnel are doing all they can to rescue them."

Around 70,000 people have been evacuated, including 300 from an area close to a dam thought to be at risk of collapse.

A hospital was left teetering by Saturday morning's 7.0 quake, with doctors and patients rushed from the building in darkness.

Isolated villages in the mountainous area of Kumamoto were completely cut off by landslides and damage to roads, with at least 1,000 people believed trapped in one area alone.

Aerial footage showed a bridge on a main trunk road had crashed onto the carriageway below it, its pillars felled.

The quake came as emergency responders were working to reach areas already affected by a 6.2 magnitude tremor that struck late Thursday.

Adding to worries was the eruption of a nearby volcano, although seismologists cautioned there was no evidence of a link and said activity was limited.

Aftershocks continued to rock Kumamoto and its surroundings, an area unaccustomed to the powerful quakes that regularly shake other parts of seismically-prone Japan.

Thursday's initial quake affected older buildings and killed nine people, but today's brought newer structures crashing down, including a municipal office in the city of Uto.

"The total number of deaths rose to 32," Yumika Kami, a spokeswoman at the Kumamoto prefectural government, told AFP.

Nearly 1,000 people have been hurt, 184 of them seriously, she added.

Tokai University announced that two of its students, who were among around a dozen trapped in a dormitory building in Minami-Aso, were now known to have died.

"We offer our sincerest prayers for the two," said a statement on its website. "We're trying to confirm the safety of other students."

At least one of those who died was killed when a fire ripped through an apartment complex in the town of Yatsushiro, a local official said.