Jakarta, March 22: Thirty people were treated for gas exposure after Mount Ijen in eastern Java belched toxic fumes from its crater, Indonesia's disaster agency said today. Spokesman Sutopo Purwo Nugroho said that dozens of residents of several villages on the volcano's slopes had to flee. The mountain is known for its stunning sulfur lake and night-time sulfur mining involving dangerous and backbreaking work by low paid labourers.

Sutopo said Ijen's summit is now temporarily off-limits to activities but the volcano's overall status remains normal. A resident of Sempol village in Ijen district said the gas spread from the volcano sometime on Wednesday evening, state news agency Antara reported. Indonesia, which straddles the seismically volatile Pacific "Ring of Fire," has more than 120 active volcanoes.