Mount Merapi in Central Java spewed hot ash on Saturday night, causing mild ash rain over Boyolali regency.
The eruption was recorded to have a maximum amplitude of 55 millimeters and a duration of 105 seconds.
Boyolali Disaster Mitigation Agency (BPBD) head Bambang Sinungharjo said the ash had fallen around Cepogo district, but preparations had been made in advance.
He said the BPBD was coordinating with the districts of Selo, Cepogo and Tamansari in anticipation of further ash rain. "The situation is under control," he said on Sunday, as quoted by kompas.com
"We have also distributed face masks to the public," Bambang said.
The Geological Disaster Technology Research and Development Center (BPPTKG) has set Merapi's alert level to waspada (caution), the second-highest level in the country's four-tiered alert system.