Concerns are rising about the risk of disease in the Indonesian city of Padang where rescuers are still trying to get to people trapped by an earthquake.
The first earthquake occurred on Wednesday at 5.16pm local time (1016 GMT). It was magnitude 7.6. A second earthquake followed on Thursday at 8.52am local time. It was magnitude 6.8.
The BBC reports about 1000 are known to have died; another 3000 are still missing. Few buildings in Padang are undamaged.
Oxfam says supplies of clean water are a problem in Padang.
Entire villages have been destroyed in remote areas of Sumatra where there have been huge landslides. People are reported to be using their bare hands to dig out the bodies.