Sirens wailed and panic spread in Pillaichavady village near Puducherry Wednesday with a warning of an impending tsunami following a massive undersea earthquake off the Sumatra coast. The administrative machinery swung into action as it was informed of a 8.2 magnitude under sea earthquake in north Sumatra in Indonesia, within five minutes of the event. Coastal communities were evacuated and relief camps were set up in Pillaichavady in Puducherry once the scientists identified the earthquake to be tsunamigenic and issued inundation maps for the coastal regions. However, this was only part of a tsunami drill to test the preparedness of the administrative machinery to face a disaster of such huge magnitude. Twentyone countries in the Indian Ocean Rim took part in the \'Indian Ocean Wave 11\' (IOWAVE \'11) exercise to simulate the events of the December 26, 2004 tsunami that left a trail of death and destruction in India, Sri Lanka, Indonesia and other Indian Ocean countries. Seventeen villages in Maharashtra and Orissa were also evacuated as part of the exercise, pti reported quoting Satish Shenai, Director of the Indian National Centre for Ocean Information Services (Incois) as said in Hyderabad. The Indian Tsunami Warning Centre and Mitigation System, housed in Incois, simulated the first earthquake of 8.2 magnitude at 6:30 a.m. and within five minutes, the National Disaster Management Authority, the Coast Guard and the Navy were alerted. Thus began the 12-hour exercise to test the preparedness of the administrative machinery to handle such disasters. Incois issued an updated bulletin giving a more precise location of the quake and raising the magnitude from 8.2 to 8.8 on the Richter Scale. Half-an-hour later the exact location of the earthquake was identified and the magnitude was revised to 9.2 on the Richter Scale. Three types of bulletins were issued -- the first for an tsunami alert, another for a tsunami watch and a final for a tsunami warning. Maps were issued for the third category and villages covered under the warning were evacuated. \'This exercise was meant for testing the communications system and preparedness for such disaster,\' Shenai said. Ten states and union territories, three nuclear plants, six port authorities, Navy, Coast Guard and the Union Home Ministry Control Room were involved in the exercise. These were the level one participants and only the administrative wings of these institutions were involved in the exercise.