Scientists said another major quake was unlikely to happen soon but the new jolts frayed nerves across the disaster zone, where the UN said building materials were urgently needed to provide shelter.

Officials also warned that while food and medicines were reaching the needy, a lack of toilets was raising fears of disease as waste was exposed openly in many areas.

"It's not a very exciting subject but it's absolutely vital," said Charlie Higgins, the UN's area relief coordinator in the quake zone. "There's no 'Latrines Sans Frontieres.'"

As the homeless braced for a ninth night out in the open, struggling in makeshift shelters, he said the survivors needed tools and supplies to build better living quarters as soon as possible.

"There is obviously a big shortfall in the amount of materials ... that have been given out and that are in the pipeline," he told AFP after an aid coordination meeting in Yogyakarta, the main city in the quake zone.

"It's not so much tents, although tents are useful in some circumstances, as it is shelter materials such as tarpaulins, bamboo, rope, tools, et cetera, that enable people to put together their own shelter solutions."

The Indonesian government said it would provide more than 160 million dollars to rebuild homes in the zone, as more international aid poured in to cope with the tens of thousands of injured and homeless.

The United Nations has said 100 million dollars is needed over the next six months to cope with the disaster, and said Saturday it was in a "race against time" to help survivors struggling to get food, shelter and health care.