The death toll from a volcano eruption in Indonesia has risen to 22 after nine more bodies were discovered, a search and rescue agency official said Tuesday.

Mount Marapi on the island of Sumatra spewed an ash tower 3,000 metres (9,800 feet) -- taller than the volcano itself -- into the sky on Sunday.

Hundreds of rescuers have worked for days to find the missing hikers, which numbered 10 on Tuesday before the local rescue agency's announcement that most had been found, bringing the days-long search closer to an end.

"Nine of 10 missing victims were found dead this afternoon and at the moment, they are being evacuated. There is one remaining victim currently in the search," Abdul Malik, head of Padang Search and Rescue Agency told AFP.

The dead were carried down the mountain in bodybags over several days, rescue officials said.

Images shared by Basarnas showed a rescue team of six in orange jackets and hard hats carrying a body down the side of the volcano on Tuesday.

Some of the 75 hikers on the mountain during the eruption were found alive and carried down, with multiple suffering burns and fractures.

One survivor spoke of his panic after the eruption began.

"I was zig-zagging, going down around 30 to 40 metres" to a trekking post, Ridho, 22, told AFP from a bed in a nearby hospital.

"The eruption sounded loud, I took a look behind then immediately ran away as everyone did. Some jumped and fell. I took cover behind the rocks, there were no trees there."

The volcano was still erupting as of midday on Tuesday, according to officials, slowing the rescue efforts of more than 200 personnel.

Later in the day, rainfall and volcanic smoke were still blocking a view of Marapi, according to an AFP journalist.

- 'Mountain of Fire' -

Ahmad Rifandi, head of Marapi's monitoring post, told AFP Tuesday it had observed five eruptions from midnight to 8:00 am (0100 GMT).

"Marapi is still very much active. We can't see the height of the column because it's covered by the cloud," he said.

The head of Indonesia's volcanology agency, Hendra Gunawan, said Marapi has been at the second level of a four-tier alert system since 2011, and a three-kilometre exclusion zone had been imposed around its crater.

He appeared to blame hikers on Monday for going too close to the crater, saying the agency recommended no human activities in that zone, and emphasised that "severe impacts" were reported for victims within one to 1.5 kilometres from the crater.

Officials said the hikers had registered through an online booking system, but others may have been on illegal mountain routes.

Those killed were severely burned and forensic workers were preparing to identify the dead by dental and fingerprint records, or based on marks on their bodies, said Eka Purnamasari, an official from the West Sumatra police medical unit.

The search would last seven days until all of the hikers were found, rescue officials said.

Indonesia experiences frequent seismic and volcanic activity due to its position on the Pacific "Ring of Fire", where tectonic plates collide.

Mount Marapi, which means "Mountain of Fire", is the most active volcano on Sumatra island and one of the archipelago's nearly 130 active volcanoes.

Locals described the carnage when the volcano burst to life on Sunday.

"The villagers were shocked because of the thundering noise, then there was a jolt and also a boom," said Adrizal, head of local village Nagari Lasi.

"The villagers were very traumatised by the eruption."