The death toll from a tsunami that pummelled remote Indonesian islands is expected to pass 500, an official said Thursday as questions mounted over whether a warning system had failed.
Hopes were fading for hundreds of people still listed as missing after a huge wave triggered by a powerful earthquake hit the remote Mentawai islands Monday off the west coast of Sumatra.
Meanwhile, on the island of Java in the centre of the disaster-prone archipelago, a volcano which this week killed 32 people again spewed ash and deadly heat clouds, volcanologists said.
Disaster response officials said bodies were being found on beaches and coastal areas in Mentawais, where the tsunami had washed away entire villages.
"Ten minutes after the quake we heard a sound just like an explosion from outside -- it was then we realised there was a tsunami," said 20-year-old housewife Chandra on North Pagai, one of the two worst-hit islands.
Dazed and exhausted, she was searching for her six-month-old baby boy, who has not been seen since the disaster. Neighbours found her husband's body in their village of Muntei Baru Baru.
"I know he's dead but I keep praying he's still alive. I'm so tired. I've not eaten for two days," she told AFP.
The official death count stood at 343 with 338 missing, but disaster management official Ade Edward said the toll would rise, possibly by as much as 200.
"Of those missing people we think two-thirds of them are probably dead, either swept out to sea or buried in the sand," he told AFP.
"When we flew over the area yesterday we saw many bodies. Heads and legs were sticking out of the sand, some of them were in the trees. If we add another 200 to the toll it would be at least 543 dead."
President Susilo Bambang Yudhoyono visited the area to console the victims, some of whom broke down as they told the ex-general how they had lost everything to the sea.
A ship bearing aid including food, water, medical supplies as well as body bags arrived Thursday at Sikakap, on North Pagai.
An AFP photographer on board saw hundreds of villagers being treated at a medical clinic, many requiring stitches to open cuts suffered as they were tossed around in the surging waves.
Survivors said they had almost no warning that the three-metre (10-foot) wall of water was bearing down on them, despite the laying of a sophisticated network of alarm buoys off the Sumatran coast.
The expensive system of tsunami warning buoys was established after the 2004 Asian tsunami, which killed at least 168,000 people in Indonesia alone.
An official tsunami warning was issued after Monday's 7.7-magnitude quake but it either came too late or did not reach the communities in most danger.
A Jakarta-based official responsible for the warnings blamed local authorities on the Mentawais for failing to pass on the alert, telling reporters: "We don't feel there was any mistake."
Medical personnel were arriving on helicopters but stormy weather has hampered the delivery of badly needed aid by boat. Troops and at least five warships have also been dispatched.
Australia announced that Jakarta had accepted a million dollars in aid for victims of both disasters, while the United States and several Asian countries have also offered help.
On Java, Mount Merapi erupted again late Thursday but there were no initial reports of damage. Officials said hot ash and gas had spewed down the southern slope, where most of the 32 people killed on Tuesday lost their lives.
The fresh eruption is bad news for more than 50,000 people crammed into uncomfortable temporary shelters outside the danger zone.
"The threat is still there which is why the status still stay at red," government volcanologist Surono said.
The slopes of the mountain were an eerie wasteland earlier Thursday, with houses burnt and flattened, trees scorched and stripped of leaves and the stench of rotting bodies strong in the air.
One of the people killed was an 83-year-old elder appointed by the sultan of Yogyakarta to appease the sacred volcano's restless spirits. He was killed as he prayed in his house after refusing the order to evacuate.