The Jakarta Post
The Center for Volcanology and Geological Hazard Mitigation (PVMBG) says Sinabung's lava dome has grown after it erupted for a third time in a week.
Mt. Sinabung, located in Karo regency, North Sumatra, spewed volcanic ash at 12:33 p.m. Sunday after erupting on Saturday evening and last Tuesday.
A Mt. Sinabung monitoring post officer, Armen Putera, said the three eruptions had resulted in the volcano's lava dome growing.
He said the lava dome was not visible when the volcano initially erupted on Tuesday, but lava had flowed out of the crater for hours on Saturday.
Armen said that during Sunday's eruption, lava was not visible as it was obscured by fog.
"We estimate that the eruption was not as big as the one five days earlier," Armen told The Jakarta Post on Sunday.
He said his office had detected quite strong pressure of magma from inside the mountain, as magma started to move to the surface.
He warned that it was an indication that there could be a larger eruption and advised local residents and visitors against entering the danger zone.
Karo Disaster Mitigation Agency (BPDB) head Martin Sitepu said his officers were patrolling the danger zone to warn people against entering.
Sinabung roared back to life in 2010 after being dormant for 400 years. After another period of inactivity, it erupted once more in 2013 and has remained highly active since.