JAKARTA: Eleven climbers were found dead in Indonesia on Monday and 12 were missingafter the Marapi volcano erupted in West Sumatra, a rescue official said, as search operations - which were halted temporarily over safety concerns - resumed.

Three survivors were found on Monday along with the bodies of the 11 climbers, out of 75 who were in the area at the time of Sunday's eruption, said Jodi Haryawan, spokesperson for the search and rescue team, adding they were all local climbers.

"We have continued to search for the 12 missing climbers until this evening. We have not decided when we are going to stop the operation," Jodi said in a phone call, adding they would continue evacuating the three survivors and bodies of climbers.

There were 49 climbers evacuated from the area earlier on Monday and many were being treated for burns, Jodi said.

It took around four to six hours to evacuate one dead body from the volcano, Jodi said, adding: "It's very difficult."

The 2,891 metre (9,485 ft) high volcano spewed ash as high as 3 km into the sky on Sunday.

Marapi is one of the most active volcanoes on Sumatra island and its most deadly eruption was in April 1979, when 60 people were killed. This year, it erupted between January and February and was spewing ash around 75 metres-1,000 metres from the peak.

Authorities raised the alert to the second-highest level and prohibited residents from going within 3 km of the crater.

Video footage showed a huge cloud of volcanic ash spread widely across the sky, and cars and roads covered with ash.

A small eruption on Monday morning prompted the search to be temporarily suspended for a few hours. The eruption spewed volcanic ash around 800 metres high.

Indonesia sits on the Pacific's so-called "Ring of Fire" and has 127 active volcanoes, according to the volcanology agency.