Volcanic ash from Indonesia's smoldering Mount Sinabung has blanketed parts of Medan, the provincial capital of North Sumatra, forcing residents to wear masks.
The head of the local disaster mitigation agency, Subur Tambun, said Wednesday that smoke spewing from the mountain was being carried by winds toward Medan. So far, the ash fall is not seriously disrupting daily life, he said, including flight operations at the city's airport.
Medan with a population of 3.4 million is Indonesia's third-biggest city after Jakarta and Surabaya.
TV footage showed ash blanketing parts of the city which is about 50 kilometers (31 miles) northeast of the mountain.
According to the Sinabung monitoring post, there were seven hot ash avalanches Wednesday that slid up to 3,500 meters (10,500 feet) southeastward. The ash cloud billowed 2,000 meters (6,560 feet) high.
The 2,460-meter (8,070-foot) volcano has spewed hot lava almost daily since its alert status was raised early this month to the highest level. More than 10,300 villagers whose homes are in the danger zone have been evacuated since then to safer areas.
Mount Sinabung is one of about 130 active volcanoes in Indonesia, which is prone to seismic upheaval due to its location on the Pacific "Ring of Fire," an arc of volcanoes and fault lines encircling the Pacific Basin.
It has sporadically erupted since 2010, after being dormant for 400 years. An eruption last year killed at least 17 people.