After nine tremors were felt within a span of two hours in the Andaman and Nicobar Islands on Monday, the count reached to twenty medium intensity quakes in a span of 11 hours on the same day.

As per the National Centre for Seismology (NCS), all the tremors were between 4.5 and 5.5 Richter scale.

The first jolt occurred at 5.14 AM measuring 4.9 Richter scale, followed by another with a magnitude of 5, a few minutes later.

The last jolt was recorded at 3.44 PM with a magnitude of 4.8, said the NCS report.