Quakes were also felt in Singapore, Thailand and was centered 33 km beneath the ocean.
According to the tsunami centre's warning, quakes of such a magnitude "have the potential to generate a widespread destructive tsunami that can affect coastlines across the entire Indian Ocean basin". They also said that a wave of 0.2m height is expected.
Reports reveal that a tsunami is likely to hit the Little Nicobar Islands. Tamil Nadu, Andhra and Andaman are also on alert.
Meanwhile, no casualties have been reported so far and People have been asked to move away from coasts.
Tremors were felt across Chennai, Bangalore, Kolkata, Patna, Thiruvananthapuram, Kochi, Cuttack, Bhubaneshwar and several other cities situated on the eastern coast of India.