The Civil Aviation Authority of the Philippines (CAAP) said flight restrictions around Mayon Volcano in Albay will remain in place until Saturday morning.
The aviation regulator extended a Notice to Airmen covering airspace from the surface up to 11,000 feet in the vicinity of the volcano.
The restriction took effect Friday morning and is set to lapse at the same time the following day.
CAAP said the continued limitation is a precautionary measure in response to heightened volcanic activity.
Flight controls around Mayon have been enforced since December as monitoring agencies observed signs of unrest.
The Philippine Institute of Volcanology and Seismology (Phivolcs) raised the volcano’s status to Alert Level 2 due to increased rockfalls and ground movement.
Phivolcs has cautioned that these developments point to a higher likelihood of eruptive activity.