Local authorities prepared 2,000 blankets and distributed masks to displaced people. They also have set up a health command post, Nugroho said. He added there was an urgent need for cooking ware, food for babies and medicine.
On Monday, gray smoke still billowed from the peak of North Sumatra's tallest volcano, carrying ash eastward. Authorities asked residents to remain alert for other potential eruptions.
Mount Sinabung's last eruption in August 2010 killed two people and forced 30,000 others to flee. It caught many scientists off guard because they had failed to monitor the volcano, which had remained quiet for four centuries.
There are more than 129 active volcanoes in Indonesia, the world's largest archipelago nation. It is prone to seismic upheaval due to its location on the so-called "Ring of Fire" a series of fault lines stretching from the Western Hemisphere through Japan and Southeast Asia.