Mount Barujari, child of Mount Rinjani in West Nusa Tenggara province, spewed a column of ash up to two km into the sky on Tuesday, forcing hundreds of tourists to leave the area, Xinhua news agency quoted the Head of Emergency Unit of the province Agung Pramuja as saying.
"There have been many tourists evacuated. Still 13 others have not returned," he told Xinhua.
He said the data was obtained from officials at the Gunung Rinjani National Park.
Authorities have declared a three km radius around the crater as a danger zone, according to Sutopo Purwo Nugroho, spokesman of the national disaster agency.
A total of 1,023 foreign holiday makers and 56 visitors were at the site when the eruption took place, Sutopo said.
"Scores of holiday makers are reluctant to leave the zones. They knew it is dangerous but they insisted to stay as they wanted to film the eruption," he said.
Indonesia, an archipelago country home to over 17,500 islands, has 129 active volcanoes.
