India on Wednesday said there was no likelihood of a tsunami being formed anywhere in the Indian Ocean region after an earthquake of 8.9 magnitude hit waters off western coast of northern Sumatra in Indonesia.

Intially, the Earth Sciences Ministry and the National Disaster Management Authority issued a tsunami warning for Andaman and Nicobar Island and an alert to coastal areas of Andhra Pradesh and Tamil Nadu.

Later, in subsequent bulletins, the two organisations virtually ruled out tsunami in Andaman and Nicobar Islands and elsewhere in the country.

"There is no specific threat. It was a watch and alert. There is no likelihood of any tsunami in the Indian Ocean region," NDMA Vice President Sashidhar Reddy said.

No upward movement

He said the earthquake that struck the Sumatra islands was not the kind of tremors that usually triggers tsunami tidal waves. "It is the kind of strike and slip earth quake which does not trigger tsunami. There was no vertical displacement of water under the sea," he said.

The initial projections issued by the Indian Tsunami Early Warning Centre (ITEWC) showed the tidal waves triggered by the quake hitting parts of Nicobar, Komatra and Katchal minutes after it struck the region at 14:08 IST. The ITEWC also issued an alert for coastal Tamil Nadu, Andhra Pradesh and the Andaman islands forecasting the arrival time of the first wave. Strong tremors were felt in Chennai and some other nearby areas. People in multi-storeyed apartments and those working in high rise buildings rushed out to open areas.

Indonesia

Indonesian President Susilo Bambang Yudhoyono said there were no immediate reports of casualties or damage in Aceh, the Indonesian province closest to the earthquake.

US monitors issued said the quake appeared to have only generated small waves.

Victor Sardina, a geophysicist with the US Pacific Tsunami Warning Center in Hawaii, said a tsunami was 'not anywhere near' as large as the devastating tsunamis that struck Asia in 2004 and Japan last year.

He said the tsunami measured a mere 35 centimeters (14 inches) near Padang, Indonesia, but could swell to as high as a metre (three feet) near Sri Lanka, adding that US scientists were still carefully monitoring the situation.

Earlier, the center said 'earthquakes of this size have the potential to generate a widespread destructive tsunami' but that it was not yet clear if such a tsunami had actually been generated.

The US Geological Survey said an 8.6-magnitude earthquake struck off the coast of Sumatra at 2:38 pm (0838 GMT) at a depth of 33 kilometers (14.2 miles), revising earlier reports of a deeper, stronger quake.

The epicenter was some 435 kilometers (270 miles) from Banda Aceh, Indonesia, one of the hardest-hit areas in the December 26, 2004 tsunami that wrought devastation across the Indian Ocean and killed some 220,000 people.

The earthquake that caused the 2004 tsunami had a magnitude of 9.2, but also a much stronger vertical component, whereas Wednesday's earthquake was more horizontally directed, Sardina said.

Last year, a 9.0-magnitude earthquake caused a tsunami and nuclear disaster in Japan, killing some 19,000 people.