Eight volcanic earthquakes were recorded at Mount Kanlaon in the past 24 hours, including "explosion-type earthquakes," according to the Philippine Institute of Volcanology and Seismology.
Kanlaon shot ash as high as 1.5 kilometres into the sky in three eruptions that lasted nearly half an hour on Saturday, but no injuries were reported.
"After the eruption, moderate emission of white steam plumes that rose 400 metres high before drifting west-north-west to north-west was observed," the institute said in its latest bulletin.
It said it was closely monitoring Kanlaon and stressed the need for the public to keep out of a 4-kilometre radius danger zone and for pilots to avoid flying close to the volcano's summit.
Kanlaon has erupted about 30 times since 1919. In 1996, three trekkers were killed when the volcano suddenly ejected ash and fiery rocks while they were near the summit.
Last week, Mount Bulusan in the eastern province of Sorsogon, also spewed ash and steam into the air, with no injuries reported.
- DPA