OJIYA, Oct 24: Thousands of weary and frightened residents in northern Japan spent a second night in shelters, cars or in the open on Sunday after Japan's deadliest earthquake in nine years killed at least 21 people.

More than 2,000 were injured when the 6.8 magnitude quake and a series of powerful aftershocks struck rural Niigata prefecture, about 250km north of Tokyo, on Saturday, setting off landslides, wrecking houses and buckling railway tracks.

Several aftershocks struck the region on Sunday. The quake, coming days after a typhoon killed at least 80 people, is the deadliest in Japan since the Kobe earthquake.

In Tokyo, where the government set up a crisis centre, officials were trying to contact remote areas and arrange to transport food, water, blankets, heaters and other necessities.

The quake and aftershocks shook buildings in Tokyo on Saturday but there were no reports of injuries or major damage. -Reuters