A volcano on the remote Indonesian island of Halmahera has spectacularly erupted, spewing a grey ash cloud into the sky, and people from seven nearby villages have been evacuated, authorities said on Sunday. Mt. Ibu erupted on Saturday evening, sending ash 4 km (2.5 miles) high, as streaks of purple lightning flashed around its crater, according to information and images shared by Indonesia's volcanology agency. Indonesia's volcanology agency raised the alert level of the volcano to the highest level on Thursday, after Ibu erupted multiple times earlier this month.