Thousands of residents in Indonesia’s East Java were on high alert on Monday after a violent eruption at the island’s tallest volcano.

Schools and businesses shut across the Philippine capital on Monday as a volcano belched clouds of ash across the city and seismologists warned an eruption could happen at any time, potentially triggering a tsunami.

A volcano suddenly erupted on Tuesday morning in Indonesia’s Mount Sinabung in North Sumatra province, local media reported.

A volcano has erupted in the eastern Indonesian island of Sulawesi, only days after a devastating earthquake and a subsequent tsunami hit that same area, killing more than 1,400 people and leaving the island’s survivors on a desperate struggle to stay alive.