A view of a tsunami-hit area in South Pagai sub-district in Indonesia's Mentawai islands, October 28. — Photo by Reuters

NORTH PAGAI, Indonesia: Indonesia battled Friday to deliver aid to remote islands where a tsunami has killed over 400 people, as bodies lay strewn on beaches and buried in debris days after the wave hit.

Disaster response officials believe the final death toll from the huge wave that hit the Mentawai island chain off the west coast of Sumatra Monday could pass 500, with many of the victims sucked out to sea as the tsunami receded.

Almost 13,000 people are living in makeshift camps on the islands after their homes were wiped out in the wave, which was triggered by a powerful 7.7 magnitude earthquake.

Elsewhere in the disaster-prone archipelago, the nation’s most active volcano, Mount Merapi, was spewing lava and ash, threatening residents who may have returned to their homes after an eruption on Tuesday killed 34 people.

“It shot heat clouds at 6:10 am as far as 3.5 kilometres down its southeastern slopes and followed this with ash rain,” volcanologist Heru Suparwoko told AFP.

He said the heat clouds were “definitely dangerous” for people who had refused to obey orders to evacuate the danger zone on the island of Java or who had returned to tend to their livestock and property.

Some 50,000 people have fled to temporary shelters but officials expressed frustration that many were returned to their homes on the volcano’s slopes during the day, despite the threat of another deadly eruption.

“It’s very difficult to convince people here that the volcano’s threat is serious,” health ministry crisis centre head Mudjiharto told AFP.

On the Mentawais, a picturesque destination for foreign surfers but an otherwise poor and neglected part of Indonesia, bodies were being found buried on beaches and even stuck in trees.

Disaster management official Agus Prayitno said the death toll had risen to 408, as hopes dimmed for another 303 still listed as missing after the wave flattened villages and homes.

“When we flew over the area yesterday (Wednesday) we saw many bodies. Heads and legs were sticking out of the sand, some of them were in the trees,” another disaster official Ade Edward said Thursday.

Indonesia initially refused offers of foreign aid but Australia on Thursday announced that Jakarta had accepted a million dollars worth of assistance for both disasters.

The United States and several Asian countries have also offered help.

The European Commission released 1.5 million euros (two million dollars) in aid and UN Secretary General Ban Ki-moon said the United Nations stood ready to assist in any way.

“Indonesia is currently addressing a multitude of emergencies, whose cumulative impact is putting local capacity under severe strain,” European aid chief Kristalina Georgieva said.

The European money will help around 65,000 people in the Mentawais and another 22,000 affected by the volcano.

Bad weather has hampered efforts to ferry aid such as tents, medicine, food and water to the islands by boat from the nearest port of Padang, which is more than half a day away even in the best conditions.

Indonesia has dispatched troops and at least five warships to the region but there is believed to be a need for more helicopters and boats to reach the most isolated communities, some of which lack roads and wireless communications.

“Our staff have been waiting in Padang since Monday night to reach the remote area. They are now still in Padang,” World Vision emergency response director Jimmy Nadapdap said.

President Susilo Bambang Yudhoyono visited the area Thursday, having cut short a visit to Vietnam to attend a regional summit, telling distraught survivors that aid was on its way.

Indonesia and foreign donors have spent millions of dollars on an elaborate tsunami warning system since the 2004 wave which killed more than 168,000 people on Sumatra and nearby islands.

But survivors of Monday’s disaster said the only warning they received was the roaring sound of the wave itself as it sped towards them shortly before 10 pm.

Many felt the earthquake but a tsunami alert issued minutes later in Jakarta failed to reach the villages in most danger.

An official responsible for the warnings dismissed reports that the system was faulty and blamed local authorities on the Mentawais for failing to pass on the alert.

The Indonesian archipelago is studded with scores of active volcanoes and stretches from the Pacific to the Indian oceans, spanning several tectonic plates meeting on a so-called “ring of fire”.

According to the US Geological Survey, Monday’s earthquake was “the latest in a sequence of large ruptures along the Sunda mega thrust” including the 2004 quake.