JAKARTA: A massive 7.9-magnitude earthquake struck off the west coast of Indonesia's Sumatra island on Wednesday, toppling buildings and briefly triggering a tsunami alert across the Indian Ocean region.
There was no immediate word on the extent of casualties and damage, but there were reports of buildings toppled or cracked open from the force of the quake around 300 kilometres from the epicentre.
In the capital Jakarta 600 kilometres further south, high-rise towers wobbled, water sloshed from swimming pools and panicked office workers ran into the streets. Elsewhere, power was knocked out and phone lines went dead.
The huge quake -- anything over magnitude 7.0 is considered to have the possibility for massive damage and loss of life -- was felt in neighbouring Singapore, Malaysia and Thailand, where office buildings swayed and shook.
The US Pacific Tsunami Warning Centre said an alert was in effect for the entire Indian Ocean area including Indonesia, India, Sri Lanka, Thailand and the Maldives, all affected by the devastating December 2004 Asian tsunami.
But the Indonesia meteorology agency later said the danger had passed.
The undersea quake erupted around 1640 IST some 100 kilometres southwest of the city of Bengkulu at a depth of roughly 15 kilometres, the United States Geological Survey said.
"I saw some parts of houses crumbled to the ground but not huge damage. People ran out of their homes," said Ayu Claudia, a resident of Bengkulu in a brief conversation before the phone lines went down.
A reporter in the city from ElShinta radio said that patients at a maternity hospital were being shifted outside, and that the streets were clogged with people trying to flee to higher ground.
"People are currently in front of their houses ... The main streets are busy with vehicles, cars and motorcycles, heading to higher areas," she said before her phone was also cut.
Budi Darmawan, a policeman in the Indonesian town of Mukomuko on the west coast of Sumatra, said buildings three storeys and higher had collapsed and that tsunami warning sirens had failed to activate.
"Buildings of three floors or more are either fissured or collapsed," he told ElShinta radio.
He said police raced through the streets on motorcycles, warning residents to move quickly to higher ground.
"The lights are out. We cannot see anything," Slamet Purwanto, a resident in Bengkulu district, told the Detikcom online news agency.
Malaysia, Sri Lanka, the Maldives and India all issued separate tsunami warnings telling residents to move away from the Indian Ocean coastline.
Indonesia has endured repeated major quakes in recent years, including the 2004 quake that unleashed a tsunami across the Indian Ocean. It killed over 220,000 people in a dozen countries including some 168,000 in the Indonesian province of Aceh alone.
In May 2006, a quake rattled the country's main island of Java, killing more than 5,700 people and destroying some 300,000 homes. Two months later, another quake on Java killed more than 600.
