TOKYO • Isolated villages in mountainous areas near Kumamoto City were completely cut off by landslides and damage to roads.
Television footage showed fires, power outages, and gaping holes in the earth.
Scores of people were believed trapped in one settlement in the wake of the devastating earthquake that struck Japan's southern island of Kyushu in the early hours yesterday, reported Agence France- Presse.
"I felt strong shaking at first, then I was thrown about like I was in a washing machine," said a Tokai University student who was taking shelter in a university gym in the village of Minamiaso with 1,000 other students and residents.
"All the lights went out and I heard a loud noise. A lot of gas is leaking and while there hasn't been a fire, that remains a concern," the student told Japanese media, reported Reuters.
Aerial footage showed a bridge on a main trunk road had crashed onto the carriageway below it, its pillars felled. A hospital was left teetering by the quake, with doctors and patients rushed from the building in darkness.
The authorities warned residents of landslides and said houses weakened by the quake could collapse, while footage showed a partially collapsed apartment building in Kumamoto.
Thursday's initial quake affected older buildings and killed nine people, but yesterday's brought newer structures crashing down, including a municipal office in the city of Uto.
Mrs Hisako Ogata, 61, was evacuated with her daughter to a nearby park , where some 50 other people sat on blue plastic sheets, after the latest quake. "We left my house as we could not stay due to continuous jolts," Mrs Ogata told Agence France-Presse. "It was so scary," she said. "Thank God we are still alive."
Self Defence Forces personnel in the town of Mashiki, close to the epicentre, provided food and water.
"I don't mind standing in line. I'm just thankful for some food," said a man in his 60s waiting in line for a meal.
Mr Mike Firn, a journalist, told CNN he felt the earthquake in a building some 900km away from the centre. "The building started shaking," he said. "It was swaying quite strongly for over a minute... Buildings were swaying and cracking."
The deadly earthquakes on Thursday and yesterday even breached the walls of Kumamoto Castle, which had previously withstood bombardment and fire in its four centuries of existence.
Seismologists fear that the series of earthquakes could trigger temblors in other active faults in the island, which extend eastward into central Japan, reported the Asahi Shimbun newspaper.
The United States Geological Survey estimated that there was a 72 per cent likelihood of economic damage exceeding US$10 billion (S$13.5 billion), adding that it was too early to be specific.
Japanese companies, including electronics giant Sony and Honda Motor, extended production halts announced after Thursday's disaster, reported Reuters.