People stand near a collapsed shopping mall after an earthquake hit Padang, on Indonesia's Sumatra island September 30, 2009. [Agencies]

Indonesia's government announced $10 million in emergency response aid and medical teams and military planes were being dispatched to set up field hospitals and distribute tents, medicine and food rations. Members of the Cabinet were preparing for the possibility of thousands of deaths.

Rustam Pakaya, head of the Health Ministry's crisis center, said "thousands of people are trapped under the collapsed houses."

Kalla said the worst-affected area was Pariaman, a coastal town about 40 miles (60 kilometers) northwest of Padang. He gave no details on destruction or deaths there.

Local television reported more than two dozen landslides. Some blocked roads, causing miles-long traffic jams of cars and trucks.

On Tuesday, a powerful earthquake off the South Pacific islands of Samoa, American Samoa and Tonga _ thousands of miles (kilometers) from Indonesia， spawned tsunami that killed more than 100 people. Experts said the seismic events were not related.

Both Indonesia's Aceh province, which was devastated in the 2004 tsunami with 130,000 dead, and Padang lie along the same fault. It runs the along the west coast of Sumatra and is the meeting point of the Eurasian and Pacific tectonic plates, which have been pushing against each other for millions of years, causing huge stress to build up.

Scientists have long suggested Padang would suffer a similar fate to Aceh in the coming decades. Some predictions said 60,000 people would be killed， mostly by giant waves generated by an undersea quake.

The dire predictions spread alarm across Padang, which was struck by an earthquake in 2007 that killed dozens of people.