The death toll from a tsunami that pummelled remote Indonesian islands soared to 343 on Thursday as questions mounted over whether an elaborate warning system had failed.
President Susilo Bambang Yudhoyono was heading to the disaster zone, where fears were growing for hundreds still missing after a huge wave triggered by a powerful earthquake Monday hit the Mentawais off the west coast of Sumatra.
Hundreds of kilometres (miles) away, a mass funeral was held for some of the 32 people killed when the nation's most active volcano erupted on Tuesday.
Disaster response officials said bodies were being found on beaches and coastal areas in the Mentawai island chain, which took the full force of the tsunami as it washed away entire villages.
West Sumatra disaster management official Ferry Faisal said "343 people were killed and 338 are still missing".
A ship bearing aid including food, water, medical supplies as well as body bags arrived Thursday at Sikakap, on North Pagai island, one of the two worst-hit islands in the Mentawai group.
An AFP photographer on board said hundreds of villagers being treated at a medical clinic, many requiring stitches to open cuts suffered as they were tossed around in the surging sea.
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 warning system was instituted 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.
One survivor, 32-year-old farmer Borinte, said the wave slammed into his community on North Pagai island minutes after residents had felt the quake.
"About 10 minutes after the quake we heard a loud, thunderous sound. We went outside and saw the wave coming. We tried to run away to higher ground but the wave was much quicker than us," he told AFP on Wednesday.
He said he managed to stay alive by clasping to a piece of wood, but his wife and three children were killed.
Medical personnel were arriving on helicopters but boats bearing aid have been hampered by bad weather around the islands, which are about half a day's journey away from the port of Padang on Sumatra.
Troops and naval personnel have been dispatched to the area. Indonesian western fleet commander Marsetio said at least five warships were on their way.
The United States and several of Indonesia's neighbours including Australia have pledged help for a nation that often finds itself battling calamity, although Jakarta says it does need foreign assistance.
On the central island of Java, rescuers have pulled the bodies of at least 32 people from tombs of fine grey ash after Mount Merapi erupted on Tuesday, including the elderly spiritual gatekeeper of the "Mountain of Fire".
More than 20 of the victims were buried in a mass grave at a ceremony Thursday in Sidorejo village, south of the volcano.
"They found my mother's body inside her house while my sister was lying on the ground outside," said Dali Sri, 45, tears streaming down her face.
Others were laid to rest in private ceremonies, including an elder known as Grandfather Marijan, the royal guardian of the volcano, whose body was lowered into a grave to the sound of chanted Islamic prayers.
The 83-year-old ignored orders to leave and died as he prayed at his home on the volcano's slopes.
"He was like a boat captain who would never surrender although he must pay with his life," said local resident Ani Wijayanti, 47.
Government volcanologists said the mountain had been relatively quiet since the deadly eruptions, and officials said more than 50,000 people had fled to cramped temporary shelters around the nearby city of Yogyakarta.
But there were fears for the fate of thousands of people who have refused to leave.
The slopes of the mountain were an eerie wasteland on Thursday, with houses burnt and flattened, trees scorched and stripped of leaves and the stench of rotting bodies filling the air, according to an AFP reporter at the scene.