Washington/Tokyo, Aug 11 (DPA) A tsunami watch was cancelled for South and Southeast Asia after an earthquake measuring 7.6 on the Richter scale struck in the Indian Ocean, while a second earthquake, with a magnitude of 6.6, struck in the Pacific Ocean off the coast of Japan Tuesday.

The earthquake in the Indian Ocean was centred about 262 km north of the Andaman Islands and took place at 1956 GMT, the US Geological Survey (USGS) in Denver, Colorado, reported. It struck in the early Tuesday (local time) and was 30 km below the earth's surface.

The Pacific Tsunami Warning Centre in Hawaii issued a tsunami watch for Bangladesh, India, Indonesia, Myanmar and Thailand, saying the earthquake was strong enough to produce a tsunami along coastlines within 1,000 km of its epicentre.

However, it cancelled the warning a few hours later 'as sea levels indicated that a significant tsunami was not generated'.