Eleven people, including four schoolchildren, were killed Saturday after they were engulfed by scorching ash clouds spat out by Indonesia's Mount Sinabung in its biggest eruption in recent days, officials said.

Eight people were found dead in Sukameriah village, near Mount Sinabung on the western island of Sumatra, four or whom were high school students on a sightseeing trip to the volcano, said Sutopo Purwo Nugroho, the spokesman for the National Disaster Management Agency.

Three other bodies were recovered from the village later in the afternoon and were taken to hospital for identification, Nugroho added.

Photographs taken by an AFP repoter at the scene showed apocalyptic scenes of corpses covered in ash just yards from a fallen motorcycle as masked rescuers wearing battled through the fumes to reach them.

Officials fear there could be more fatalities from Saturday's eruptions, but due to the high potential of lethal heat clouds spewing from the mountain, the search and rescue has been grounded, officials said.

"We suspect there are more victims but we cannot recover them because the victims are in the path of the hot (ash) clouds," Nugroho said.

Three other people, a father and his son as well as another man, suffered friom burn injuries, Karo district official, Johnson Tarigan, told AFP.

He said the three were in an intensive care unit of a local hospital.

Mount Sinabung had shown a reduction of activity since mid-January.

But it erupted again on Saturday morning, sending hot rocks and ash up to 2,000 metres (16,000 feet) into the air, blanketing the surrounding countryside with grey dust, said volcanologist Kristianto, who like many Indonesians goes by one name.