A graphic with map of Asia summarising the destruction wrought by the earthquake and tidal wave.(AFP)

Tsunamis triggered by a massive earthquake in Indonesia smashed into coastal areas of the Indian Ocean ring nations Sunday, destroying villages and flooding cities and killing more than 11,000 people.

The 8.9-magnitude earthquake, the most powerful one in four decades, struck just before 8:00 a.m. local time (0100 GMT) off the west coast of the Indonesian island of Sumatra, about 1,620 kilometers northwest of Jakarta, according to the US Geological Survey. It was followed by a series of powerful aftershocks.

The death toll is increasing as counting of bodies washed up on beaches is continuing while thousands were reported missing. Tens of thousands fled the coasts for higher ground, fearing aftershocks and further flood surges.

In Sri Lanka, one of the worst hit countries, the death toll climbed to 4,500 and about 1 million people were displaced. The Sri Lankan government declared a national disaster.

Sri Lankan President Chandrika Kumaratunga, who was on a private visit to Britain, is to cut short her visit and to return to Sri Lanka, the president office said.

Kumaratunga has called for international assistance in dealing with the country's worst ever humanitarian disaster.

The Sri Lanka Rupavahini Corporation has launched a relief program to aid the victims of tidal waves. The organizers of the campaign asked the general public to donate any material which can be distributed among the victims.

In Indonesia, the health ministry said at least 4,185 people were killed and hundreds more were missing.

The ministry's officials said at least 3,000 of the people killed were in the provincial capital Banda Aceh, either from flooding or quake damage.

About 100 were killed in neighboring north Sumatra province and on the island of Nias, to the west of Sumatra close to the epicenter of quake.

Some 50,000 people had fled their homes and taken refuge in government offices or other buildings on higher ground while hundreds were still unaccounted for, officials said.

In India, officials put the death toll to 2,300 in the southern states of Tamil Nadu, Andhra Pradesh and Pondicherr as waves swept away boats, homes and vehicles.

Hundreds, mainly poor fishermen, were missing in the wake of the dawn quake whose aftershocks took a heavy toll in the Andaman and Nicobar islands as well as in the states of Tamil Nadu, AndhraPradesh and Kerala.

Tamil Nadu Chief Minister J. Jayalalitha said 1,500 deaths have been recorded in her state.

Kerala accounted for some 100 deaths and Andhra Pradesh some 200, according to Home Minister Shivraj Patil.

This was one of the worst tragedies that have hit India since the January 2001 when a quake of Gujarat killed nearly 25,000.

Indian Prime Minister Manmohan Singh assured states hit by the devastating tsunamis of all support and assistance for relief and rehabilitation efforts and appealed to the people to remain calm.

In Tamil Nadu, the highest casualties were recorded in Nagapattanam, 788, followed by Cuddalore, 290 and Kanyakumari, 261.

Chennai, Tamil Nadu's capital, has reported 128 deaths and seawater seeped into the nuclear power plant at Kalpakkam, around 50 km away, forcing it to shut down. A special Indian Army unit was mobilized to deal with the situation and the Crisis Management Group said the plant was "fully safe".

Some young men carry a body of a woman killed by tial waves in the coastal area of Chennai, capital of south India’s Tamil Nadu Dec. 26. Over a thousand people have been killed in earthquake-caused tidal waves in Tamil Nadu, Andhra Pradesh and Andamand and Nicobar Islamabd in south India, Indian Home Minister Shivraj Patil said here on Sunday. And he told reporters after a meeting of the Crisis Management group that Tamil Nadu was the "worst affected" with possibly over 800 people killed. (Xinhua Photo)

Thousands of people fled their homes in Chennai after the tremors continued for several minutes and seawater entered their properties, catching them unawares and triggering unprecedented panic.

The tidal waves caused flooding in central areas and a power shortage in thickly populated parts. The Chennai airport was shut and all flights to and from the city were canceled till Sunday evening.

Officials in Andhra Pradesh capital Hyderabad confirmed 60 deaths but said they expected the toll to rise as reports of missing fishermen were pouring in from dozens of villages along the state's 1,000-km-long coastline.

Some 700 fishermen were reported missing in Prakasam district alone and Chief Minister Y.S. Rajasekhara Reddy announced the payment of 100,000 rupees as compensation to the kin of the dead.

Hundreds of families were evacuated from the low-lying areas of Andhra Pradesh and fishermen were warned not to venture out to sea as more aftershocks were expected.

At Machlipatnam in Krishna district, 25 bodies, most of them women and children, were found at Manginapudi beach. Most of the dead were Hindus who had come for a dip in the sea on the eve of the full moon during the holy month of Margasirsa.

Orissa and West Bengal were also hit, with the latter state reporting two deaths near Kolkata.

Some 45,000 people on the Car Nicobar and Great Nicobar islands were affected, officials said. Three AN-32 transport planes of the Indian Air Force were sent with relief materials to the islands.

The airport at Port Blair suffered some damage, the Crisis Management Group said. Flights resumed after the navy, which is in charge of the airport, cleared it. "If necessary, additional flights will be organized to evacuate tourists," the group said in a statement.

In Thailand, the government officials said, 257 people have been dead and more than 5,447 injured and many missing in the country's southern resort islands after tsunamis caused by a massive earthquake off Indonesia.

Thai navy has rushed to the southern islands swept by the tidal waves, sending out helicopters and HMS Chakrinaruebet in a bid to salvage tourists and local residents.

Rear-Admiral Pheerasan Watcharamoon, deputy commander of the 2nd Navy Division, said that they had sent out fully-equipped ships to pick up tourists and local residents from Phi Phi and several other islands in the vicinity.

Nearly 4,000 people still stranded on the Phi Phi island, said Admiral Surin Rerng-arom, chief of staff for the Royal Thai Navy.

In Malaysia, at least 42 people were killed on the resort island of Penang, police and government officials said.

Malaysia and Myanmar also reported casualties from the quake and waves.