Huge aftershocks rumbled across Indonesia's Sumatra island on Thursday, as rescue teams sped to the area after a massive 8.4-magnitude earthquake killed at least six people.
The follow-on shocks, including one as strong as magnitude 7.8, drew new tsunami warnings from Indonesian authorities and panicked thousands of people who had already spent the night outdoors afraid of being buried alive.
Dozens of people were also reported injured in Wednesday night's huge quake, and officials said they feared the death toll could still rise. In many places, phone lines and electricity were down.
The quake was strong enough to shake buildings in Thailand and Malaysia, and set off a tsunami alert as far away as eastern Africa - raising memories of the December 2004 tsunami catastrophe that killed 2,20,000 people.
But the initial reports from some parts of the Sumatran coast suggested that this nation of 17,000 islands, victim of some of the world's deadliest earthquakes in the past, may have been spared the worst.
The health ministry's crisis centre said six people had been confirmed dead and at least 38 had been injured in the quake, which hit underwater some 300 kilometres off the Sumatran town of Bengkulu.
"My wife was washing the dishes and my two sons were taking a bath," said Samsul Anwar, sitting in a tent at the main hospital in the town. He had rushed home when he felt the ground shake violently.
"The roof of the house had collapsed, hitting my wife in the head," Anwar said, comforting his son lying injured on a stretcher.