Japan volcano: Rescuers search Mount Ontake for missing climbers

More than 500 people are searching for people still missing on Japan's Mount Ontake, authorities say.

The volcano erupted on Saturday, while hundreds of hikers were climbing it.

Most escaped but some were trapped by the ash clouds. At least 36 people are believed to have died.

The BBC's Rupert Wingfield-Hayes says there are thought to be at least 20 people still on the mountain.