Chennai, Aug 13 - An earthquake measuring 5.7 on the Richter scale, described as an aftershock to Tuesday's quake, jolted this southern metropolis Thursday and brought people rushing out of their homes and offices.

Director of India Meteorological Department (Chennai) W.P. Gopal said the quake was the eighth aftershock following the 7.8 level temblor that had occurred off the Andaman and Nicobar Islands Tuesday.

Thursday's aftershock at 2.51 p.m. was severe enough to bring people rushing out of their offices and homes here, though no casualties or damage was reported.

The epicentre of the aftershock was also reported to be undersea off the Andaman and Nicobar Islands, at latitude 14.1 degrees north and longitude 92.9 degrees east.

Gopal said the previous seven aftershocks had been in the range of 4.5-4.8 on the Richter scale, and more were expected.