Several people have been injured by hot ash spewed during an eruption of Indonesia's most volatile volcano.
A witness said up to 20 people were taken away for treatment for their injuries.
Subandriyo, chief vulcanologist in the area, said Mount Merapi started to erupt just before dusk on Tuesday local time. It had rumbled and groaned for hours.
Scientists have warned that pressure building beneath Merapi's lava dome could trigger one of the most powerful blasts in years.
Thousands of residents on the slopes have been evacuated. But most who fled were the elderly and children, while adults stayed to tend to homes and farms on the mountain's fertile slopes.