Indonesian villagers brace for potential volcanic eruption
Meanwhile residents in Candisewu village in the district reported sightings of animals such as monkeys, snakes and anteaters fleeing the slopes in past few days.
"Maybe the air near the crater is getting hot, so the animals are running down," resident Mahfud told the state-run Antara news agency.
He said residents had taken it as a sign that they should be prepared for a possible eruption.
The 1,731-metre (5,712-foot) volcano last blew in 1990. It has claimed more than 15,000 lives since 1500, including around 10,000 when it erupted in 1568.
Although Mount Kelut's slopes are sparsely inhabited, the peak is a popular domestic tourist destination and is located on a densely-populated plain.