Merapi's eruption appeared to have been triggered by a minor earthquake and authorities had not raised the volcano alert status from normal, said Sutopo Nugroho, spokesman for the National Disaster Management Agency.
"There had been no increase in Merapi's activity before," he said.
A series of eruptions at Merapi, located near the central Javacity of Yogyakarta, left more than 350 people dead and forced 300,000 people from their homes in 2010.//DPA