JAKARTA, Indonesia - An extremely powerful earthquake rocked northern Indonesia Sunday, sparking massive tidal waves and potent aftershocks across the region, killing 160 in Sri Lanka. More than a dozen people were reported killed elsewhere and scores others were reported missing, officials and witnesses said.
The U.S. Geological Survey said a magnitude-8.5 quake - one capable of massive damage - struck off the coast of the Indonesian island of Sumatra at 8 a.m. Sunday.
Soon after, massive waves crashed into several countries across the region, and aftershocks in the magnitude-7 range were sparked, the USGS said.
Waves crashed into coastal villages over a wide area of Sri Lanka - some 1,000 miles west of the quake's epicenter - killing 160 people and displacing thousands of others, an official said.
The deaths occurred in the northeastern districts of Muttur and Trincomalee, which were inundated by waves as high as 20 feet, said D. Rodrigo, a Muttur district official.
Fourteen people died and many were missing in popular southern Thailand resorts, said Sorajak Chusaeng, of the Narenthorn Center of the Public Health Ministry. The center also reported that people were swept away in Phuket by a tsunami with waves surging as high as 16 feet.
In Indonesia, witnesses told Jakarta's el-Shinta radio station that nine people were killed in the northernmost province of Aceh, and several shops and small buildings had collapsed. There was no way to immediately confirm the report because of severed communication links.
"The ground was shaking for a long time," resident Yayan Zamzani told the station. "It must be the strongest earthquake in the last 15 years."
Don Blakeman, and earthquake analyst with the USGS, said large tidal waves frequently follow quakes like the one seen in Indonesia, noting that a powerful quake in Alaska four decades ago caused waves that killed people as far away as Japan.
He told The Associated Press that aftershocks are another concern. "We do expect large aftershocks after a large earthquake like this."
The Bangladesh Meteorological Department said a powerful earthquake jolted a wide area of that country early Sunday, but there were no immediate reports of casualties or damage. The quake was reported to be a magnitude-7.3.
In India, hundreds of people fled as tidal waves hit in southern coastal areas, officials said.
Press Trust of India news agency said at least 15 people were feared missing in Pattinapakkam and Thirvattriyur districts of Madras, the capital of southern Tamil Nadu sate. The rising sea water flooded huts of nearly 2,500 fishermen living in low lying areas of Madras, also known as Chennai, police said.
Indonesia, a country of 17,000 islands, is prone to seismic upheaval because of its location on the margins of tectonic plates that make up the so-called the "Ring of Fire" around the Pacific Ocean basin.
The quake struck just three days after an 8.1 quake struck the ocean floor between Australia and Antarctica, causing buildings to shake hundreds of miles away but no serious damage or injury.
Quakes reaching a magnitude 8 are very rare. A quake registering magnitude 8 rocked Japan's northern island of Hokkaido on Sept. 25, 2003, injuring nearly 600 people. An 8.4 magnitude tremor that stuck off the coast of Peru on June 23, 2001, killed 74.