Children burst down the stairs in a rush for safety from the second floor of a school near Aceh's provincial capital Banda Aceh, where more than 60,000 were killed in the tsunami.

As school bells rang out, dozens of children ran into the road covering their heads, following marked escape routes as volunteers shouted "evacuate".

"With exercises, we can prevent, rather than cure," said 34-year-old participant and local village official Rizky Firmansyah.

"It's better like that I think, because it's better for us to anticipate than to have things that we don't want to happen."

The drills simulated a repeat of the magnitude 9.2 earthquake which struck off the west coast of Indonesia's Sumatra island on December 26, 2004, sparking giant waves that killed over 200,000 people in 14 countries.

The UN-organised drills saw hundreds of students and volunteers run to safe houses, including one four-storeys high, when the mock quake struck.

- 'Extremely important' -

The drills -- which took place in two villages as hundreds of observers watched -- were part of a tsunami summit of experts organised by the United Nations cultural agency (UNESCO).

Nearly 20 years on from the disaster, the UN is trying to get 100 percent of coastal communities prepared for a repeat tsunami by 2030.

"We must ensure the next generation remains informed, prepared, and resilient," Ardito Kodijat, a UNESCO official and head of the Indian Ocean Tsunami Information Centre, told AFP.

"Ensuring community preparedness requires regular drills."

Indonesia is one of the most disaster-prone nations on earth.

The archipelago nation lies on the Pacific "Ring of Fire", where tectonic plates collide and many of the world's volcanic eruptions and earthquakes occur.

UNESCO experts say the world is much safer today from the threat of massive tsunamis due to early warning systems that were lacking in 2004.

But the agency has also warned coastal communities to stay alert.

"While we have made significant strides, the nature of this hazard requires us to remain vigilant," Vidar Helgesen, executive secretary of UNESCO's intergovernmental oceanographic commission, told delegates in Banda Aceh on Monday.

Indonesia's meteorology, climatology and geophysics agency (BMKG) also took part in the exercises meant to test operating procedures, communications and evacuation preparedness.

Many people are believed to have lost their lives in countries around the Indian Ocean basin because of a lack of warning and preparedness.

So such drills are vital for locals, even though tsunamis are infrequent.

"This is extremely important for this community," said Cutraa Rasmanidar, a 21-year-old graduate working as a volunteer.

"I think it's important because it's reflective, so we can remember what happened in the past."