As an Indonesian volcano continues to spew, more than 21,000 people have been evacuated. Mount Sinabung in North Sumatra continues to erupt for the second consecutive day as aircraft are diverted away from the region.

With a giant ash plume now forming, thousands of villagers have been forced to leave their homes on the slopes of the mountain heading to mosques, churches and emergency shelters. Heavy, gray soot blankets homes and crops near the base of the volcano and the air is reportedly thick from the sulphur smell. Mt Sinabung has not erupted since 1600, so scientists have little information on its eruption patterns to date, however it was admitted that prior to this weekend’s eruptions the volcano had not been closely monitored.

As a result of the eruption, so far two have died, one from breathing complications and the other a heart attack. Two have suffered injuries during traffic accidents as ambulances, buses and trucks moved about the region as part of rescue operations. Similar to other volcanoes near the Sumatra fault line, the volcano could pose a significant threat, said disaster researcher Erick Ridzky.

He said that should there be a larger blast, the ash cloud could obscure visibility affecting air traffic as far as Malaysia and Singapore. Already flights heading to Medan, the provincial capital, have been diverted due to poor air quality, said the Indonesian Transportation Ministry. Government volcanologists said that the core issue was that the volcano has not been studied and it is unclear what set it off. They added that it was unclear as to what to expect from the eruption.