Tsunami survivors sit at a destroyed house at Parorogat, Pagai island, West Sumatra, Indonesia, on Thursday. (Achmad Ibrahim/Associated Press)

Relief planes dropped boxes of dried noodles onto tsunami-ravaged Indonesian islands Friday because storms and a shortage of vessels made helicopter and boat deliveries almost impossible days after the wave killed more than 400 people.

Hundreds of kilometres away, a volcano on the island of Java that killed 35 people this week erupted five more times Friday, sending searing clouds of ash cascading down its slopes.

Four days after the tsunami crashed into the Mentawai islands off Sumatra, details of survivors' misery and new accounts of the terrifying moments when the wave struck were still trickling out from the area, which was cut off by rough seas for nearly two days after the 7.7-magnitude earthquake that churned up the killer wave.

'Noise and chaos'

A group of surfers told of huddling and watching in horror as a roaring wall of water crossed a lagoon and slammed into their three-storey thatch-roofed resort. The power of the wave shook the building so hard they feared it would collapse. All 27 people at the resort survived — five of them by clinging to trees.

"It was noise and chaos. You can hear the water coming, coming, coming," Chilean surfer and videographer Sebastian Carvallo said Friday. "And then before the second wave hit the building, everyone was, like, screaming and when the wave hit the building you could only hear people praying."

Carvallo said at least two of the waves were at least five metres high. Officials have said there was only one wave three metres high, but several witnesses have described one or several taller than that.

Tsunami survivors make their way past damaged houses Thursday after their village was hit by Monday's earthquake-triggered tsunami at Parorogat village, Pagai island, West Sumatra, Indonesia. (Achmad Ibrahim/Associated Press)

Dozens of injured survivors of the tsunami languished at an overwhelmed hospital Friday, including a newly orphaned two-month-old boy found in a storm drain. The infant, with cuts on his face, blinked sleepily in a humidified crib. Hospital workers named him Imanual Tegar. Tegar means "tough" in Indonesian.

"We need doctors, specialists," nurse Anputra said at the tiny hospital in Pagai Utara — one of the four main islands in the Mentawai chain slammed by Monday's tsunami.

Relief workers in Hercules planes air-dropped food, mostly boxes of instant noodles, onto the hardest-hit areas in the Mentawais on Friday. Local television footage showed survivors running to pick up the boxes.

West Sumatra Gov. Irwan Prayitno told reporters that heavy storms had cut the visibility of helicopters and made seas too dangerous for small boats to deliver emergency supplies.

Another official said Friday that a shortage of small boats was also holding up aid. Suryadi, who is co-ordinating the aid response from West Sumatra, said tonnes of aid has reached the main towns on the worst-hit islands by helicopter, after rough seas kept boats away for two days.

More boats needed

But rescue workers say they still can't deliver much of that aid to the farther-flung coastal villages that are accessible only by foot or by sea because roads on the islands are too old or damaged for large trucks.

"We need more boats," Suryadi said. Most of the islands' craft would have been washed away by the wave and helicopters have no place to land in many of the devastated villages.

A boy salvages his belongings Friday from the ruins of his house, which was hit by the earthquake and tsunami in a village in Munte, Mentawai district, in the province of West Sumatra. (Crack Palinggi/Reuters)

Authorities on the Mentawais have gathered up about 20 traditional wooden boats that survived the tsunami and have been using them to ferry supplies to cut-off villages, Soetrisno, deputy of emergency mitigation of the national disaster management agency, told Elshinta radio station.

But Friday's heavy rains that churned up the sea made air drops the only option. The weather is also disrupting communications, making it hard to contact the islands by mobile phone or even satellite phone, Soetrisno said.

The toll from the tsunami and the earthquake beneath the Indian Ocean that spawned it rose to 408 on Friday as officials found more bodies, and 303 people were still missing and feared swept out to sea, said Agus Prayitno of the West Sumatra provincial disaster management centre.

Along with those killed by Mount Merapi's eruption this week, the number of dead from the two disasters, which struck within 24 hours of each other, has now reached 443. Officials said two more people died of burns from Tuesday's blast, bringing the volcano's death toll to 35.

After a lull that allowed mourners to hold a mass burial for victims, the volcano rumbled with three small eruptions Thursday and five early Friday, according to Subandriyo, a senior government vulcanologist. There were no reports of new injuries or damage.

At least 47,000 people who live around Mount Merapi are staying in government camps or with friends and relatives, the National Disaster Management Agency said.

The volcano's activity appeared to be easing pressure behind a lava dome that has formed in the crater, said Safari Dwiyono, a scientist who has been monitoring Merapi for 15 years.

"If the energy continues to release little by little like this, it reduces the chances of having a bigger, powerful eruption," he said.

Mount Merapi spews smoke as seen from Sidorejo village, in Klaten, central Java, on Friday. (Andry Prasetyo/Reuters)