At least 36 people are now feared dead in the aftermath of Saturday’s Mount Ontake volcanic eruption in Japan. Toxic gases are still spewing from the volcano, causing search and rescue efforts to be suspended. Twelve bodies have been reported recovered so far. The volcano erupted, seemingly without warning, shortly before midday local time on Saturday 27 September, 2014. Around 250 people were believed to be hiking on the mountain at the time of the eruption.

While the video above compresses 12 minutes of surveillance footage into 93 seconds, it’s still possible to gauge the speed with which the ash cloud overcame those trapped on the mountain. On Sunday, rescuers discovered a moonscape of ash-blanketed buildings and hillside. Search efforts were suspended on Monday as toxic fumes and swirling ash made the work too dangerous for the more than 200 firefighters and soldiers involved in the rescue effort.

Related: VIDEO: Japan’s Mount Ontake Erupts, Killing One and Injuring Dozens More

Most of the hikers were reported to have made their way down the mountainside by Saturday night local time, but another 40 to 50 remained at the top of the mountain overnight. Many of those trapped were injured, with Japan’s Fire and Disaster Management Agency reporting that 40 people were rescued with injuries such as fractures. So far, only twelve bodies have been confirmed recovered, with many reports over the weekend euphemistically referring to 31 people having “heart and lung failure,” which is understood to describe a body that has not yet been attended to by a police doctor.

The Japan Meteorological Agency reportedly released a warming of increased volcanic activity in the area on 11 September, 2014. Volcanologists have said Saturday’s eruption was relatively small: driven by super-heated steam and ash rather than lava. This is what made it much more difficult to predict with any precision. Mount Ontake is roughly 130 miles (210 kilometers) west of Tokyo on Japan’s main island of Honshu. Its last major eruption was in 1979, but there were no fatalities. In 1991, 43 people were killed when Mount Unzen erupted in Japan’s south-west.

Via NPR and The Huffington Post

Photos via Tokyo Reporter on Twitter and Alpsdake via Wikimedia