Mt. Bulusan generated a steam-driven explosion on Sunday afternoon, the Philippine Institute of Volcanology and Seismology (Phivolcs) said.
The explosion was recorded at 1:03 p.m., Phivolcs said on Twitter.
Phivolcs previously warned of more stream-driven eruptions after it ejected ash up to two kilometers high over parts of Sorsogon on Friday.
READ: Mt. Bulusan in Sorsogon spews ash
The eruption on Friday also triggered an explosion-type earthquake.
A steam-driven explosion happens when water beneath the surface is heated by magma, lava, hot rocks, or new volcanic deposits.
As of 8 a.m. Sunday, Alert Level 1 remains in effect over Mt. Bulusan. The four-kilometer radius permanent danger zone is strictly prohibited due to the possibility of sudden and hazardous steam-driven or phreatic eruptions.
Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ash from any sudden phreatic eruption can be hazardous to the aircraft.
Communities within the valleys and along river channels especially on the southwest and northwest sector of the volcano should be vigilant against sediment-laden stream flows and lahars in the event of heavy and prolonged rainfall, Phivolcs said./rga