A strong earthquake of 7.2 magnitude hit India's southern Nicobar Islands on Sunday, prompting Thailand to issue a tsunami warning for the region devastated by a December earthquake and tsunami that killed about 180,000 people.
There were no immediate reports of casualties or damages.
The epicentre of the earthquake, which hit at 9:12 p.m., was in Nicobar, Press Trust of India news agency quoted meteorologists as saying.
The quake also jolted the southern Indian state of Madras, PTI said to AP.
The region was the worst hit in India by the December tsunami.
Thailand's warning was for the Indian Ocean.