Dec. 26 (Bloomberg) -- An 8.5-magnitude earthquake that may rank among the 10 strongest in the past century struck the Indonesian island of Sumatra, unleashing tsunami waves that killed hundreds of people across India and Southeast Asia.

Six aftershocks measuring between 5.8 and 6.1 struck in the Bay of Bengal between Thailand and India, the U.S. Geological Survey reported on its Web site. Tsunami waves killed at least 214 people in Sri Lanka and left more than 10 people dead and 200 injured around the popular Thai resort of Phuket, Agence France- Presse said.

`'My mother was in the sea when the giant wave came and she escaped with only a minor bruises, thanks to help from other people,'' said Francois Goret, a French resident of Phuket whose house is on Karon beach. ''On Karon, water came at least 50 meters inland. Chairs on the beach were washed away.''

The Indonesia earthquake, which struck about 7 a.m. local time, was a magnitude 8.5 earthquake centered offshore about 1,605 kilometers (1,000 miles) northwest of Jakarta at a depth of 10 kilometers, the U.S. Geological Survey said.

The earthquake would rank among the 10 strongest recorded since 1900 if the preliminary reading isn't revised lower, according to U.S. Geological Survey data. The worst earthquake was a 9.5-magnitude temblor in Chile in 1960.

Awaiting Casualties

``We don't have confirmation of any casualties yet,'' said Fauzi, an official at the Geology and Meteorology Office in Jakarta who goes by one name only. He said the earthquake created tsunami waves as high as 5 meters (17 feet) along the north coast of Aceh province, knocking out at least one bridge.

At least 24 people were killed in Sumatra, Acehkita.com news Web site reported, citing unidentified local officials. Indonesia's government-owned Antara news agency said electricity and phone lines have been cut in the area.

The threat from tsunamis, or waves triggered by seismic activity, isn't over. ``We expect the big waves to lash Chennai and parts of Tamil Nadu for the next two days,'' A.K. Shukla, head of the Indian Meteorological Department, said in a phone interview from New Delhi. Five fisherman have been reported dead and 22 missing along India's coastal areas.

Thai Prime Minister Thaksin Shinawatra said he can't recall tidal waves of that magnitude hitting the nation's shores before. Phuket is a favorite destination for foreign tourists during the end-of-year holiday season. Some beachgoers were reportedly swept out to sea by the waves and missing.

Beaches Bashed

''Phuket was most affected, not just people bathing in the sea but people driving their cars,'' Thaksin told reporters. ''People have died, but we can't say how many yet.''

The Sheraton Grande Laguna in Phuket moved all its guests to a safe area when big waves hit hotel, staff there said. ``Every beach area got wiped out,'' Gary Halpin, 43, a New Zealander who runs a diving business in Phuket, a tourist resort area on Thailand's west coast, across the Andaman Sea from India. ``Bungalows were wiped out and the bigger buildings had windows broken.''

The Indonesian quake is the second in the world this year of magnitude 8 or greater. Last week a magnitude 8.1 temblor was recorded in the Southern Ocean between Australia and Antarctica by the U.S. Geological Survey.

Magnitude 8 earthquakes are capable of causing severe loss of life if centered near heavily populated areas. An 8.1 quake in Mexico City in 1985 killed about 9,500 people.

There were no immediate reports of damage to oil facilities in Indonesia, Southeast Asia's biggest oil producer.

``As long as you don't see any damage to the facilities, especially the oil and gas pipelines, I don't see the impact as being significant,'' said Song Seng Wun, regional economist with G.K. Goh Holdings Ltd. in Singapore.

Indonesia's 18,000 islands are prone to earthquakes because the nation sits along the Pacific ``ring of fire,'' a zone of active volcanoes and faults in tectonic plates.

To contact the reporter responsible for this story: Sue Hill in Hong Kong at shill6@bloomberg.net

Last Updated: December 26, 2004 01:42 EST