A volcano in North Sumatra of Indonesia erupted again on Tuesday, unleashing a cloud of ash and forcing about 6,000 people to flee homes, official said. Mount Sinabung located in Karo district with a height of 2,475 meters (8,120 feet) erupted in September after being dormant for three years, belching ash and smoke, and igniting fires on its slope. The volcano has been erupting intermittently ever since. The height of ash during Tuesday's eruption could not be visualized as the volcano was covered by cloud, said Sutopo Purwo Nugroho, spokesman of national disaster management and mitigation agency. But he said that hot ash was spewed to the volcano's southeast as far as 800 meters, passing through several villages on the slope. "(Fortunately), the villagers have been evacuated,"Sutopo told Xinhua by phone. "Up to today, we have displaced 5,576 people,"he said. A 3-kilometer-evacuation-zone has been declared by the authorities as they have raised the level of threat to stand by, the second highest status, following the hike of seismic activities on the mountain over recent weeks. On Nov. 3, Mount Sinabung had a major eruption, hurdling over 7, 000 meter column of ash to the sky and has been rumbling since. The Mount Sinabung volcano is among 129 active volcanoes in the vast archipelago country, which is vulnerable to seismic upheaval as it lays on the Pacific "Ring of Fire." Indonesia's most active volcano is Mount Merapi located in central Java, whose violent eruption in 2010 killed about 350 people.