Rescuers searching the hazardous slopes of Indonesia’s Mount Marapi volcano have found more bodies among the climbers caught by a surprise eruption two days ago, raising the number of confirmed and presumed dead to 23.

More than 50 climbers were rescued after the initial eruption on Sunday, and 11 others were confirmed dead. Another eruption on Monday spewed a new burst of hot ash as high as 800 metres into the air and temporarily halted search operations. 

The latest bodies were found not too far from the eruption site, estimated to be only a few metres away, said Edi Mardianto, the deputy police chief in West Sumatra province. The bodies of five climbers have been recovered, and 18 are presumed dead because they were so close to the eruption of hot gases and ash.

“The rest we want to evacuate are 18 and we expect they are no longer alive. The team will evacuate and take them to the hospital tomorrow or today to be identified,” Mardianto said Tuesday.

The rescuers are contending with bad weather and terrain constraints, as the scouring wind brings heat from the eruptions. 

A video released by West Sumatra’s Search and Rescue Agency showed rescuers evacuating an injured climber on a stretcher off the mountain and into a waiting ambulance to be taken to hospital. 

Marapi has stayed at the third highest of four alert levels since 2011, a level indicating above-normal volcanic activity, prohibiting climbers and villagers within 3 kilometres of the peak, according to Indonesia’s Centre for Volcanology and Geological Disaster Mitigation.

Tweet from @Mdh_Sna

Climbers were only allowed below the danger zone, and they had to register at two command posts or online. However, local officials acknowledged many people may have climbed higher than permitted and residents also could have been in the area, making the number of people stranded by the eruption impossible to confirm.

One hiker who was burned but lucky to survive recorded a video message that showed her face smeared in thick grey ash.

Zhafirah Zahrim Febrina, 19, was reportedly hiking with 18 student friends when the ash began raining down on them. She recorded the video while waiting for rescue crews.

“Mum, help,” she can heard saying in the footage.

Marapi spewed thick columns of ash as high as 3000 metres in Sunday’s eruption and hot ash clouds spread for several kilometres. Nearby villages and towns were blanketed by tons of volcanic debris that blocked sunlight, and authorities recommended people wear masks and eyeglasses if possible to protect themselves from the ash.

About 1400 people live on Marapi’s slopes in Rubai and Gobah Cumantiang, the nearest villages about 5 to 6 kilometres from the peak.

Marapi was known for having sudden eruptions that are difficult to detect because the source is shallow and near the peak, and its eruptions are not caused by deep movement of magma, which sets off tremors that register on seismic monitors.

Marapi has been active since a January eruption that caused no casualties. It is among more than 120 active volcanoes in Indonesia, which is prone to seismic upheaval due to its location on the Pacific “Ring of Fire,” an arc of volcanoes and fault lines encircling the Pacific Basin.

Its most deadly eruption was in April 1979, when 60 people died.

This year, it erupted from January to February and was spewing ash about 75-1000 metres from the peak.

-AAP