Even as people in coastal areas are just coming to terms with the calamity brought in by the Tsunami, the Indian Metereological Department (IMD) today said aftershocks were likely to continue 'for some more time'.The aftershocks are likely as about 15 to 20 "moderate intensity" earthquakes were experienced between last night and this morning at Nicobar Islands and Sumatra in Indonesia, an IMD release said.A moderate earthquake, measuring 6.0 on the richter scale at latitude 13.1 degree north and longitude 92.0 occured at 6.20 am at Nicobar. Another with a magnitude of 5.6 occurred at 13.6 degree north and 92.5 degree at 2.01 am at Andaman and some other areas, it said.Issuing a 'general caution' to people, asking them not to venture into low-lying places in coastal areas, since there was a likelihood of another Tsunami, the IMD said people were also being advised 'not to occupy buildings which are partially damaged or poorly constructed'.Owners of vessels were also being advised not to put out to the deep sea for the next two days, it added.