People participate in tsunami drill in Banda Aceh, Indonesia, 14 Oct 2009Eighteen countries participated Wednesday in an unprecedented tsunami drill, as the Indian Ocean Tsunami Warning and Mitigation System was tested for the first time.

Sirens wailed along the Indian Ocean beaches and crowds fled inland, as part of a multi-national drill to gauge preparedness for the next time killer waves strike the region.

In the course of 12 hours, bulletins were sent out from the Pacific Tsunami Warning Center in the U.S. state of Hawaii and relayed by Japan's Meteorological Agency.

Stewart Weinstein was the scientist on duty sending out the bulletins at the warning center in Hawaii.

"What this means for us is that it's really testing our abilities to communicate with these 18 countries," Weinstein explained. "For them, can they receive bulletins in a timely fashion from the Warning Center? But it's also for them to test their internal procedures and their standard operating procedures for how they deal with a tsunami emergency."

Some participating countries, including Indonesia and Sri Lanka, took the exercise down to the community level, conducting limited evacuations of communities.

In other nations, such as India, the drill was limited to table-top exercises for government agencies.

The scenario is meant to replicate the magnitude 9+ earthquake off the coast of Sumatra in Indonesia, which struck in December, 2004. That tsunami affected countries from Australia to South Africa, killing about 200,000 people.

This drill comes just two weeks after another tsunami struck the Samoan islands and Tonga, killing at least 183 people.

The exercise also included seismological stations and ocean sensors linked to analysis centers on shore which are supposed to quickly determine whether a public alert needs to be issued.

When an earthquake triggers a tsunami, the waves can travel as fast as 1,000 kilometers per hour.