Sirens blared, parents grabbed their children and hundreds ran to emergency shelters in Indonesia as countries bordering the Indian Ocean conducted a test Wednesday of a warning system set up after the devastating 2004 tsunami.

But at least one survivor was too paralysed by memories of the killer wave to take part in mock evacuations.

"What is this all for? My chest has gone tight and I am shaking," said Hamiyah, a 58-year-old mother who lost her in-laws, four children and five grandchildren, as the drill kicked off in Aceh, Indonesia.

Planned for 18 countries, the drill was intended to simulate a tsunami similar to the one sparked by the 9.2 magnitude quake off Indonesia in 2004, the United Nations said in a statement.

That quake generated waves that eradicated entire coastal communities, killing some 230,000 people in one of the worst natural disasters of modern times.

"When the siren sounded, I immediately thought of my child, grabbed her and ran," said Bakhtiar, 50, who lives in the village of Gampong Pie, along the Indonesian coastline in Aceh province.

In Aceh's Ulee Lheue village, which was all but wiped out by the tsunami, about 200 residents gathered at a mosque after an explosion was sounded from loudspeakers that was meant to signal an earthquake.

Around ten minutes later a siren blared out, starting the drill.

But Hamiyah refused to take part, breaking down and staying at home, rebuilt after the disaster, with her two surviving children.

"It reminds me of the past and makes me really sad. Please stop reminding us," she said, sobbing, as people ran for quake-proof emergency shelters, some carrying the "wounded," as a voice over mosque loudspeakers urged people not to panic.

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