An 8.9 magnitude earthquake off the coast of Indonesia's Aceh province has triggered a tsunami warning across the Indian Ocean.

6.20pm: The Pacific Tsunami Warning Centre cancels tsunami watch for ALL countries. Breathe easy.

6.09pm: Indonesia's disaster agency says 1 metre tsunamis have been detected in Nias island off southern Sumatra and Meulaboh in Aceh. The Andaman and Nicobar islands are also bracing for 3.9 - 4m high waves in the wake of a second earthquake off Sumatra. The tsunami alert has been extended till 6.30pm following fresh aftershocks, but has been cancelled for several countries including Singapore, Malaysia and Australia.

5.45pm: An Indonesian source tells Firstpost that the Tsunami warning is likely to be lifted in Aceh soon - There is no 1m wave so far. There is massive exodus reported from Aceh. Meanwhile in Colombo, train services have been closed and beaches, including popular tourist resorts which were badly hit last time, have been evacuated.

5.30pm: The pacific Tsunami Warning Centre has said that despite the second strong quake, they do not expect 'basin wide' damage across the Indian ocean. It has said however that a tsunami danger is seen to parts of Indonesia's Northern Sumatra coast. Meanwhile the Centre cancelled warnings for Australia, Thailand, Malaysia, Mauritius and Singapore. It said however that the warning still stood for India, Sri Lanka, Indonesia and Maldives. The updated Pacific centre warning can be accessed here.

5.09pm: Reuters has put out a report quoting a disaster management official saying that Andaman and Nicobar Islands could see waves up to 3.9 metres high following Indonesian quakes. A series of minor quakes have already hit Campbell Bay island according to The Hindu.

4.52pm: Tsunami wave of 1.06M (3.5FT) above normal sea level recorded near Meulaboh in Indonesia. Indonesia's geophysics agency has also said that they have detected a rise in sea water level in West and North Aceh of unto 0.8 meters.

4.45pm: The Indonesia geophysics agency has extended the Aceh Tsunami warning by two hours following a strong 8.1 magnitude earthquake off the coast of Sumatra. The tremors from the second quake have been felt in India as well.

4.26pm: Reports are coming in that a strong 8.1 aftershock has been reported off Sumatra Indonesian seismologists say. They have issued a fresh alert of a tsunami.Further details are awaited. Meanwhile Reuters has reported that sea water at Simeulue Island near the epicenter of the quake has been seen receding by about ten meters. USGS puts the magnitude of aftershock at 8.2; and say it struck 382 miles SSW off Banda Aceh.

4.16pm: The National Disaster Management centre has said that no waves have been noticed so far in Andaman and Nicobar and that a tsunami has been virtually ruled out according to NDMA Vice President Sasithra Reddy. However the Pacific tsunami warning centre has said that the tsunami alert for 28 countries remains in effect. Tamil Nadu and Andhra Pradesh have begun evacuating ports and beaches, and have asked fishermen not to venture out into sea. People in South Andamans have been evacuated as a precautionary measure.

Simon Boxall, from the national oceanography centre in UK, says we seem to be out of the woods with regards to tsunami and if nothing happens in the next half hour it is unlikely we will see one.

4.10pm: Union Home Secretary R K Singh has said that there is no cause for panic along India's coastline, adding that the government is ready to deal with any eventuality.

3.58pm: Beaches and ports are being evacuated in Tamil Nadu as a precautionary measure and fishermen are being asked not to venture out into the sea. Andhra Pradesh has issued a similar warning and the Andaman and Nicobar joint command has been alerted.

3.51pm: The Pacific tsunami warning centre has said that the tsunami alert for 28 countries remains in effect, and has also said that a 17cm wave is heading towards Aceh, which is not very large. However the speed of the wave is not yet known.

3.44pm: Reports coming in that water is receding along the coast of Phuket, which is a cause of worry. The airport on the southern Thai island of Phuket has also been closed. The Malaysian met department advises people living in coastal areas to evacuate and tells them to get to higher ground.

3.33pm: Indonesia's president says "no tsunami threat although we are on alert" from Aceh quake. Indonesia's disaster mitigation agency says that there is no detection of low tide that would indicate a tsunami in Aceh.

Meanwhile Bruce Pressgrave of the US Geological Survey told BBC that it was unlikely that a tsunami would be generated since this type of earthquake does not generate a column of water that could cause a tsunami.

“There’s always a hazard but with this kind of quake it reduces the risk of a tsunami,” he said.

While it was hoped that there would be no tsunami it was prudent to issue a tsunami warning given the magnitude of the earthquake, he said.

The only possibility was if the massive earthquake had resulted in an underwater landslide which in turn could cause a tsunami, Pressgrave said, adding it remained unlikely.

3.25pm: Ships anchored off the coast of Nicobar have been asked to move to high seas as a tsunami alert has been generated for 28 countries. Other preventive measures in India include the shutting of the port in Chennai, the halt of the Kolkata metro and the evacuation of beaches in certain areas. strong>IMPORTANT: It is not yet known whether a tsunami wave has been generated or not, and there is as yet, no cause for panic.

3.20pm:The Thai national diaster centre has issued a tsunami warning in Thailand and asked people of six provinces to move to higher ground.

3.03pm: The Tsunami centre in Hyderabad issues notice for evacuation of beaches, and the Kolkata metro has been stopped. There is still no information on as to whether a tsunami wave has been generated or not. The earthquake reportedly occurred at a depth of 33km off the coast of Aceh, Indonesia. The earthquake magnitude has been reversed to 8.9 and 28 countries are on alert.

2.56pm: The pacific Tsunami Warning Centre has said a tsunami watch is on for Indonesia, India, Sri Lanka, Australia, Myanmar, Thailand, Maldives, United Kingdom, Malaysia, Mauritius, Reunion, Seychells, Pakistan, Somalia, Oman, Madagascar, Iran, UAE, Yemen, Bangladesh, South Africa and Kenya.

2.50pm: Countries including Malaysia, Singapore, Nepal and Sri Lanka have all reported tremors. A spokesperson for the India National Centre for Ocean Information Services has said that the tsunami warning is just a heads up and there is nothing to worry about just yet.

2.45pm: Satish Mathur, Secretrary to Lt Governor, Andaman and Spokesperson says no casualties have been reported so far and there are no reports of damage, following reports that a tsunami was scheduled to hit Nicobar at 2.40pm.

2.32pm: An 8.9 magnitude earthquake off the coast of Indonesia's Aceh province has been felt in many countries including India and Nepal. Tremors were felt across India including Kolkata, Chennai, Bangalore, Bihar and Guwahati. A tsunami warning has been issued across the Indian ocean.

The U.S. Geological Survey said Wednesday the quake was centered 20 miles (33 kilometers) beneath the ocean floor around 308 miles (495 kilometers) from the provincial capital of Banda Aceh.

Said, an official at Indonesia's Meteorology and Geophysics Agency who goes by only one name, said a tsunami warning has been issued.

Indonesia straddles a series of fault lines that makes the vast island nation prone to volcanic and seismic activity.

A giant 9.1-magnitude quake off the country on Dec. 26, 2004, triggered a tsunami in the Indian Ocean that killed 230,000 people, nearly three quarter of them in Aceh.