Emergency aid is arriving on the northern Indonesian islands of Nias and Simeulue, where officials fear more than 1,000 people died near the epicenter of Monday's earthquake.

Aid organizations are sending tents, food, and other emergency supplies to the two islands, which took the brunt of the 8.7-magnitude jolt. Many groups still had operations in the area from the region's December 26 earthquake and tsunami.

As cleanup on Nias and Simeulue continues, authorities are evacuating the most seriously injured and counting the dead.

Officials say about 80 percent of the buildings in Nias' main city of Gunungsitoli may have been destroyed when the temblor based off Sumatra's coast shook the region Monday night. Authorities say many victims may still be trapped in the damaged structures.

President Bush and United Nations Secretary General Kofi Annan have both pledged support to the victims, along with several countries in the region including China, India, Australia, Japan, Russia, and Singapore.

Monday's quake was some 200 kilometers southeast of the December 26 earthquake, which triggered a massive tsunami that left nearly 300,000 people dead or missing on multiple coasts. Monday's temblor triggered tsunami warnings in several countries, but no giant waves.

Some information for this report provided by AP, AFP and Reuters.