Ratdomopurbo, a senior vulcanologist with the directorate of vulcanology in Yogyakarta, confirmed newspaper reports that local village authorities evacuated more than 6,000 people after the country's most active volcano emitted clouds of hot gas at the weekend. It was the first evacuation since volcanic activity increased this month.
"We did not order them evacuated," Ratdomopurbo told Reuters by telephone.
"They probably thought the eruption (on Sunday) was very dangerous because it was followed by a thick cloud of dust and so they ran away," Ratdomopurbo said.
However, he said the vulcanology directorate was not increasing the alert status from "Alert Merapi" to the highest level "Danger Merapi" because the strength of the eruption that caused the cloud was relatively small.
"The eruption on Sunday was actually much smaller than the largest one that occurred on July 11," he said.
The Kompas daily said the evacuation of the residents of eight villages was ordered by local disaster coordination authorities.
Village authorities said they arranged the evacuation of people to nearby village meeting halls after hearing automatic sirens that are designed to raise the alarm when the volcano's activity reaches a certain point.
"We heard the siren and the people immediately moved," the secretary of the Dukun sub-district, Sujarwo, was quoted as saying.
Kompas quoted vulcanologists in nearby Yogyakarta as saying the alert status of Merapi was not being changed despite it frequently emitting clouds of hot gas, which reached as high as 5,000 metres (16,000 feet) above the mountain's 2,968 metre (9,738 foot) peak.
Residents around the volcano have reported thick dust falling on their villages, with some closest to the peak saying the dust had reached a thickness of one centimetre (0.4 inch).
Ace Purbawinata, the head of the Centre for Research and Development of Volcanic Technology (BPPTK) in Yogyakarta, was quoted by the official Antara news agency as asking local residents to stop quarrying sand in the Lamat river.
Of the 60 people killed in the last deadly eruption of the volcano in late 1994, most were quarrying sand in the deep gullies that carry sand and debris down the volcano's slopes.
The gullies channel the flow of gases, lava and mud and in a sudden explosion can turn into death traps.
- Reuters - Thomson Reuters Foundation
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