BENGKULU, Indonesia — A third day of tremors left people here skittish on Friday, with some sleeping in the streets, huddled around bonfires and frightened of being indoors after the huge earthquake that struck on Wednesday.

In Bengkulu province, on the west coast of the island of Sumatra, 10 people were killed; the death toll throughout the region was at least 13. The main hospital in Bengkulu city treated 25 people, most with light injuries. By contrast, an earthquake that struck in 2001 killed about 100 people in Bengkulu. Still, with every new rumble, people wondered if they would be so lucky next time.

"There is nothing we can do, we can't stop earthquakes," said Rina Fitrie, a mother of two who had set up a tent in front of her house, which she was sharing with neighbors.

"But I worry about my house falling down. I worry about my kids," she said. "I can't keep running outside every time the ground shakes. It's easier to just stay out here."

Bengkulu, a city of less than 100,000, is normally a sleepy, relaxed place; most residents are fishermen or farmers. The usually peaceful Indian Ocean hugs the picturesque, hilly area.

But on Wednesday, about 40 miles off the coast, the ocean floor rumbled, shaking the city so powerfully that many residents strolling to mosques for evening prayers were knocked to the ground. The 8.4-magnitude earthquake was felt throughout Sumatra and in nearby Thailand, Malaysia and Singapore. It was followed by quakes registering magnitudes of 4.9 to 7.9.

The village of Argamakmur, just north of Bengkulu, was especially hard hit. Four hundred houses in the town of 2,000 people were destroyed. Mustam, the village leader, who goes by one name, said more than 90 percent of the homes were damaged beyond repair.

Argamakmur teeters on the crest of a high ridge, worsening the effects of the earthquake on Wednesday. Many of the houses were supported by wooden stilts. Residents said that when the quake started, they instinctively ran into the road, only to watch as their houses collapsed down the slope.

"We couldn't speak," Mustam said. "So many of our homes were ruined."

Despite the damage, no one in Argamakmur was killed or seriously injured.