One of the most powerful earthquakes in history has hit Asia, unleashing a tsunami which devastated coastal areas of Sri Lanka, India, Indonesia and tourist isles in Thailand, killing more than 11,300 people. The tsunami, a menacing wall of water, wreaked death, chaos and destruction across southern Asia on Sunday. Up to 10 metres high, the tsunami was triggered by an 8.9 magnitude underwater earthquake off the Indonesian island of Sumatra. "It was a terrible sight," Jayaram Jayalalithaa, chief minister of Tamil Nadu state, said after touring areas of India, where 3,000 people were killed. "I could see dead bodies all around and the devastation is of colossal proportions." Emergency services struggled around the region popular with Western tourists flying east for Christmas sunshine. Some areas were totally unprepared and tourists found their holidays turned into disaster zones while anxious families at home awaited news. In Sri Lanka, where the death toll reached 3,500, corpses floated in floodwaters, while thousands fled their homes and cars floated out to sea. Idyllic beaches were turned into fields of debris and destruction. Around 750,000 people were displaced. "I think this is the worst-ever natural disaster in Sri Lanka," N.D. Hettiarachchi, director of the National Disaster Management Centre, said of the effects of the earthquake, the worst for 40 years and the fifth biggest since 1900. The worst-hit area appeared to be the tourist regions of the south and east where beach hotels were inundated or swept away. Local media reported landmines sown during Sri Lanka's two decade civil war had been uprooted and spread by floods. Others used the mayhem to loot shops and houses, police said. In Indonesia, where 4,422 were listed as killed, raging waters dragged villagers out to sea and tore children from their parents' arms. Wailing relatives gathered around bodies in the south of India. Beaches were littered with submerged cars and wrecked boats. Shanties on the coast of Madras were under water. "The whole area has been turned into a cemetery," Chellappa, a 55-year-old fisherman in Madras, said. Television pictures showed bodies floating in turbulent, muddy seas. Nightmare Stories Tourists had nightmare stories. French holidaymaker Philippe Gilbert, at a hotel near Tangalle in the south of Sri Lanka, told private channel LCI: "I've lost my granddaughter in all of this. I was swept away by an absolutely massive wave ... I was lucky enough to get stuck in some trees and was able to hold my breath," he said. "This is one of the largest earthquakes ever on record. The situation in Sri Lanka is extremely serious," Peter Rees, of the International Federation of the Red Cross in Geneva, told CNN. "I just couldn't believe what was happening before my eyes," Boree Carlsson said from a hotel near Phuket's Patong beach in Thailand. "As I was standing there, a car actually floated into the lobby and overturned because the current was so strong," said the 45-year-old Swede. "Nothing like this has ever happened in our country before," said Prime Minister Thaksin Shinawatra of Thailand where the death toll was 310. "Death tolls are likely to increase over time," Titon Mitra, emergency response director for the CARE aid agency in Geneva, said. "I'm sure the numbers will go up." The earthquake of magnitude 8.9 as measured by the U.S. Geological Survey struck at 7:59 a.m. (00.59 a.m. British time) off Sumatra and swung north with tremors into the Andaman islands. A warning centre such as those used along the Pacific Rim could have saved most of the thousands of people who died, A USGS official said. "And I think this will be a lesson to them," he said, referring to the devastated countries. Pope John Paul said the tragedy made for a sad Christmas. Sri Lanka'S Worst Disaster Sri Lanka appealed to the world for aid, saying that one million people, or 5 percent of its population, were affected. The global Red Cross launched an immediate emergency appeal. India feared a devastating toll along its southeastern coast. In the state of Tamil Nadu alone, an official said at least 1,705 had been killed. Rescuers were searching for hundreds of missing fishermen and thousands were homeless. Television footage showed bodies, including young girls, being thrown into trucks in Madras, capital of Tamil Nadu state. Hundreds fled to higher ground with pots, pans and other meagre possessions. People carried bodies in hessian sacks to hospitals where dozens of dead already lined the corridors. In Andhra Pradesh, about 400 fishermen were feared missing and 200 Hindu devotees who had gone to the beach for a holy dip in the morning were feared dead. Almost 500 tourists were stranded on a rock in the sea off India's southernmost tip, witnesses said. In the Maldives, none of the thousands of foreign visitors holidaying in the beach paradise, was believed to have been killed although some had suffered minor injuries. In holiday islands off southern Thailand, emergency workers rescued about 70 Thai and foreign divers from the famed Emeral Cave and dozens were evacuated from around other islands. Two Thais were killed at Emeral cave. Officials said more than 600 tourists and residents were to be evacuated from Ko Phi Phi. The tiny island made famous by the 2000 film "The Beach" starring Leonardo DiCaprio was flattened. The Thai government ordered the evacuation of stricken coastal areas, which included popular beach resorts on the islands of Phuket and Krabi. Thousands were injured in Thailand. Ring Of Fire Indonesia, an archipelago of 17,000 islands, lies along the Pacific Ring of Fire where volcanoes regularly erupt. The worst affected area was Banda Aceh, the capital of Aceh province, where 3,000 were killed. More than 200 prisoners escaped from a jail when the tsunami knocked down its walls. The earthquake was the world's biggest since 1964, said Julie Martinez, at the USGS in Golden, Colorado. "It is multiple earthquakes along the same faultline." The tsunami, meaning "harbour wave" in Japanese, was so powerful it reached across the ocean to smash boats and flood areas along the east African coast.