Residents and rescuers inspect a building destroyed by earthquake Wednesday in Padang, Sumatra island, Indonesia. The massive 8.2-magnitude earthquake triggered a small tsunami in western Indonesia on Wednesday, authorities said, and warnings were issued across much of the Indian Ocean region. A second powerful earthquake struck Indonesia today but the window for a tsunami closed with no reports of destructive waves.

Padang, Indonesia ? The second powerful earthquake in as many days shook western Indonesia today, collapsing buildings in a coastal city and triggering tsunami alerts around the region.

At least nine people were killed and 49 injured in the twin tremors, which caused tall buildings to sway in at least three countries.

On Wednesday, a strong earthquake shook Southeast Asia, collapsing buildings, killing at least five people and injuring dozens in Indonesia. That tremor triggered a small, nondestructive tsunami off the coastal city of Padang on Sumatra, the Indonesian island ravaged by the 2004 tsunami disaster. A tsunami warning was issued for wide areas of the region and nations as far away as Africa.

Today’s magnitude-7.8 quake rattled the same area of Sumatra and caused extensive damage in Padang.

“Many buildings collapsed after this morning’s quake,” Fauzi Bahar, the mayor, told El Shinta radio. “We’re still trying to find out about victims.

Thousands of frightened people piled in trucks or sought shelter on high ground.

Rafael Abreu, a geologist with the U.S. Geological Survey in Colorado, said the quake today did not appear to be an aftershock to the 8.4-magnitude temblor the day before. But the centers of both were close together.

“We are not calling it an aftershock at this point. It’s fairly large itself. It seems to be a different earthquake,” Abreu said.

“The quake seems to be pretty shallow,” he said. “These are the quakes that can produce tsunamis.”

Indonesia issued a tsunami warning, lifted it and then reissued it. Australia’s Bureau of Meteorology issued a warning that unusual waves could hit Christmas Island early today, but locals said that there was no sign of a tsunami about an hour after the predicted time.

“The danger has passed,” said Linda Cash, a manager at the Christmas Island Visitors Center. “There was no wave or damage or anything.”

However, Cash said police were out early today warning people to stay away from the beaches.

The USGS said the new quake was centered about 125 miles from Bengkulu, a city on Sumatra. It occurred at a shallow depth of about six miles and struck at 6:49 a.m.

After Wednesday’s quake, frightened people fled their homes and ran inland, fearing a repeat of the 2004 earthquake and tsunami off the coast of Sumatra that struck a dozen nations around the Indian Ocean. That disaster killing an estimated 230,000 people in a dozen nations, most of them in Aceh province on Sumatra.

“Everyone is running out of their houses in every direction,” Wati Said reported by cell phone from Bengkulu, a town 80 miles from the quake’s epicenter. “We think our neighborhood is high enough. God willing, if the water comes, it will not touch us here. … Everyone is afraid.”

Telephone lines and electricity were disrupted across a large swath of Indonesia, making it difficult to get information about damage and casualties.