No fewer than 34 persons have been confirmed dead while scores of others were missing following floods on Sumatra island in western Indonesia

Hours of heavy rain caused flooding in two districts in West Sumatra province on Saturday evening and sent sweeping ash and large rocks down Mount Marapi, the most active volcano on the archipelago’s Sumatra island.

“Until now our data shows that 34 people died: 16 in Agam and 18 in Tanah Datar. At least 18 others are injured. We are also still searching for 16 other people,” West Sumatra disaster agency spokesman Ilham Wahab told AFP.

He said the search effort involved local rescuers, police, soldiers and volunteers.

Agam and Tanah Datar districts were hit with flash floods and cold lava flow at around 10:30 pm (1530 GMT) on Saturday, according to Basarnas search and rescue agency.

Cold lava, also known as lahar, is volcanic material like ash, sand and pebbles carried down a volcano’s slopes by rain.

Earlier, Basarnas said 12 people had died including several children.