Students wearing masks to protect themselves from volcanic ash from Sunday's Mount Sinabung eruption, as they play with rattan rings at their school at Tiganderket village in Karo district, Indonesia's north Sumatra province Nov 4, 2013. The volcano erupted for the third time in as many months on the western Indonesian island of Sumatra, forcing hundreds of villagers to evacuate, officials said. Mount Sinabung spewed a 7-km (4.3-mile) column of ash into the air on Sunday, prompting authorities to impose a 3-km evacuation radius. The school pictured is outside of the evacuation zone. [Photo/Agencies]