Mount Sinabung in Indonesia has erupted, spewing black ash and smoke into the sky over Sumatra island. Gray ash covered several villages after Monday’s eruption, and authorities distributed masks to residents to protect themselves. People were advised to refrain from activities in nearby villages in Karo district in North Sumatra province and areas within 6 kilometers of the summit. No casualties, evacuations or disruptions to flights were reported. Indonesia’s Geological Agency raised the alert to the second-highest level for volcanic activity and expanded the safe zone around the mountain. Sinabung has had increased volcanic activity recently, and the agency’s chief said a larger eruption could occur.