Eighteen countries around the Indian Ocean have held a mass drill aimed at testing tsunami early warning systems.
The UN-backed drill simulated the 2004 quake off the coast of Sumatra which killed more than 200,000 people, half of them in Indonesia’s Aceh province.
The exercise comes two weeks after a tsunami in the Pacific Ocean killed almost 200 people in Samoa, American Samoa and Tonga.
UN officials are due to issue an assessment of the drill within days.
Exercise Indian Ocean Wave 09 tested warning systems and preparedness in nations in Asia, Australasia, the Middle East and Africa.
In 2004, the only warning most people had was the sight of a giant wave
Along the coast of Aceh hundreds of people – including schoolchildren – carried out a mock evacuation as ambulance crews stood watch.
But some residents were too traumatised by memories of the 2004 tsunami to take part.
“My chest has gone tight and I am shaking,” Hamiyah, 58, who lost her in-laws, four children and five grandchildren, told AP news agency.
“If there’s another disaster, I prefer to take shelter in the mosque so that if I die, I’d die in the mosque,” Halimah, 43, told Reuters news agency as she watched the drill, but refused to take part.
Not all 18 participating countries involved the public in the exercise. The authorities in India and Thailand said they had concentrated instead on co-ordination between government agencies.
Officials from around the region declared the drill a success.
Since the 2004 tsunami, early warning systems ranging from beach sirens to deep ocean monitor buoys have been set up at a cost of about $150m (£94m), officials say.
Much of the money for the equipment has come from international donors, including Germany, Japan and China.
The test will determine whether the Indonesian authorities have spent that money wisely, and whether the local population is prepared for a future catastrophe, says the BBC’s Karishma Vaswani in Banda Aceh.