The earthquake of magnitude 8.9 as measured by the US Geological Survey first struck at 7:59am local time off the coast of the northern Indonesian island of Sumatra and swung north with multiple tremors into the Andaman islands in the Indian Ocean.

The US Geological Survey says it is the fifth biggest earthquake since 1900.

A wall of water up to 10 metres high set off by the tremor swept into Indonesia, over the coast of Sri Lanka and India and along the southern Thai tourist island of Phuket, leaving at least 650 people feared dead, officials said.

The earthquake was the world's biggest since 1965, said Julie Martinez, geophysicist for the US Geological Survey.

"It is multiple earthquakes along the same faultline," she said.

The worst-hit area appeared to be the tourist region of Sri Lanka's south and east and the chairman of the John Keells hotel chain said five of his hotels had been badly flooded.

At least 500 were feared dead in Sri Lanka, the National Disaster Management Centre said.

"According to the information we have so far, 500 people have been killed and the death toll is going to be high - it will likely be over 1,000," said N D Hettiarachchi, director of the centre.
[...]
Officials now say 84 are dead and 400 wounded in southern Thailand.
[...]
Along the southern Indian coast, as many as 74 people were killed and many injured by a tsunami there, hospital and government officials said.

Officials said 400 fishermen were missing in the south.
[...]
Two people died and some 100 people were hurt in the capital of India's Andaman islands when tidal waves hit, the state's chief secretary said.
[...]
The wave swept into the low-lying Maldive islands whose coral atolls are a magnet for tourists, flooding two-thirds of the capital Male, said chief government spokesman Dr Ahmed Shaheed.

"The damage is considerable. The island is only about three feet above sea level and a wave of water four feet high swept over us," he said.

"It is a very bad situation. It is terrible," he said.

"We have no communications with some of the outlying atolls. At this stage we fear the worst. We are trying to send boats to assess the damage, but our resources are stretched to the limit."
[...]
As many as 72 people were killed and 79 injured on in Indonesia's Aceh province on northern Sumatra island, local government and hospital officials said.