"We called on the people to keep away from the rivers, particularly when it is raining," Makwan, head of emergency and logistic of BPBD, stated here on Saturday.
However, Makwan cautioned that any cold lava flood arising may not reach villages around the slope of the volcano.
"If there is a cold lava flood, settlement areas would not be at risk, as rivers, whose upstream areas are located on the slopes of the volcano are deep enough," he explained, adding that the Sabo Dam built around the volcano had adequate capacity.
Sabo Dam is a structure that blocks, flattens, or diverts lava flows along the river path that might be inundated by lava.
Mt Merapi located on the border of the provinces of Central Java and Yogyakarta erupted at 6.21 a.m. local time on Saturday, emitting a column of hot ash up to 1.5 kilometers high, and the wind blew the ash towards the west.
The volcano is on alert status since May 21, 2018.
Head of Yogyakarta Search and Rescue (SAR) Brotoseno affirmed that his team had been readied as a precautionary measure against further activities of Mt Merapi. Related news: Mount Merapi spews lava avalanche as far as 850 meters in distance
Related news: Merapi unleashes lava flowing 700 meters upstream of Gendol River
EDITED BY INE