A rumbling volcano on Indonesia's Sumatra island spewed hot gas and rock on Tuesday, forcing hundreds of people to flee their homes, an official said, according to Reuters. Mount Sinabung had erupted nine times since Monday afternoon, with hot gas and dust flows reaching 2,500 metres down its flanks, said Sutopo Purwo Nugroho, a spokesman for the National Disaster Management Agency. The latest eruption prompted more than 300 residents to flee to safer ground, he said. More than 19,000 people have been displaced since the volcano began its most recent activity in September. The 2,460-metre volcano in the province of North Sumatra had been dormant for 400 years before it erupted in August 2010. There are nearly 130 active volcanoes across the Indonesian archipelago.