PORT BLAIR, India (Reuters) - A major quake of magnitude 7.6 struck in the Indian Ocean off India's Andaman Islands early Tuesday, triggering a tsunami watch for India, Myanmar, Indonesia, Thailand and Bangladesh.
"The room shook for around 20 to 30 seconds, it was quite strong," said Reuters correspondent Sanjit Kumar Roy in Port Blair, capital of the islands.
He said that in the northern part of Andaman Island, people ran out of their houses in panic. Police said there had been no reports so far of any damage.
The U.S. Geological Survey said the quake, initially reported as a magnitude 7.7, struck at 1:55 a.m. (8:05 p.m. British time on Monday). It was shallow, at a depth of 20.6 miles (33 km), and was centred 160 miles (260 km) north of Port Blair.
The U.S. National Oceanic and Atmospheric Administration's Pacific Tsunami Warning Centre issued a tsunami watch for the region.
"Earthquakes of this size have the potential to generate a destructive local tsunami and sometimes a destructive regional tsunami along coasts located usually no more than a thousand kilometres (about 600 miles) from the earthquake epicentre," the tsunami centre said in its bulletin.
However, an official at the Indian National Centre for Ocean Information Services said a tsunami warning had not been issued by his department.
"We have not issued a tsunami alert and are monitoring the water level changes in the region at the moment," Ajay Kumar told Reuters by phone.
The Andaman and Nicobar Islands are a chain of small islands hundreds of miles east of India in the Indian Ocean.
A 7.6 magnitude quake is classified by the USGS as a major earthquake and is capable of widespread, heavy damage.
An even bigger quake in the Indian Ocean in 2004 caused a tsunami that killed some 228,000 people.
In Indonesia, a meteorology agency official said his agency was monitoring the Aceh area on the tip of Sumatra. So far there had been no reports of a tsunami in Indonesia but it could take two hours for one to reach the coastline.
(Editing by John Chalmers and Angus MacSwan)
