The volcano at Mount Sinabung on the western island of Sumatra in Indonesia has erupted for the second time spewing smoke and ash up into the air. Local experts say the second eruption occurred in the early morning local time and it was bigger than Sunday's.

"It lasted about 15 minutes. The smoke and ash reached at least 2,000 metres (6,600 feet)," government volcanologist Agus Budianto said.

Evacuation and relief

The authorities have ordered everyone within a six-kilometer "danger zone" to leave. Over 21,000 persons have been evacuated so far and have been accommodated in temporary shelters. At least two people died in the first eruption on Sunday.

Witnesses said a strong smell of sulphur has filled the air. A number of the evacuees were believed to be suffering from respiratory problems, fever and diarrhea. A local Red Cross worker said more masks, mineral water, medicines and foodstuffs were immediately needed.

The transport ministry has also ordered airlines to avoid the Mount Sinabung region.

Scientists surprised

Mount Sinabung had been inactive for four centuries. Its sudden eruption has taken scientists by surprise. Volcanologist Agus Budianto said the volcano's long period of dormancy made it difficult for experts to predict its behavior, but they are monitoring it closely now.

"We must remain on alert for unpredictable events since this mountain has been dormant for hundreds of years."

Indonesia lies on the Pacific "Ring of Fire", where the meeting of geological plates causes high volcanic and seismic activity.

The country has nearly 130 active volcanoes and 69 are listed as dangerous.

du/AFP/dpa/AP
Editor: Grahame Lucas