A major 7.7 magnitude earthquake struck the Indian Ocean on Sunday near India's Nicobar Islands, the US Geological Survey said.
The quake hit at 1.26am local time (1926 GMT) at a depth of 35 kilometres with the epicentre around 160 kilometres west of the Nicobar Islands.
The Pacific Tsunami Warning Centre issued a tsunami watch for all areas of the Indian Ocean following the quake.
The warning said earthquakes of this size had the potential to cause destructive local and sometimes regional tsunamis, but added it was not yet known that a tsunami had been generated.


