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.