The Mayon Volcano in Albay exploded two times yesterday morning, the Philippine Institute of Volcanology and Seismology (Phivolcs) reported as it warned residents to stay out of the six-kilometre radius permanent danger zone.
The phreatic or ash explosions occurred at 8:17 a.m. and 8:28 a.m. that generated grayish to grayish white ash plumes 600 meters and 200 meters above the crater, respectively based on Phivolcs' latest bulletin.
Phivolcs director Renato Solidum said the explosions were possibly triggered by the sudden degassing of magma inside the volcano's chamber.
Mayon remains under Alert Level 2 after its full-blown eruption episodes that started January and simmered down in March early this year.
Solidum said the explosions would not warrant yet the raising of its alert level to three.
These minor ash explosions are still within Alert Level 2 parameters," he stressed.
This means that Mayon is at a moderate level of unrest, Phivolcs said.
Before the events, Phivolcs said Mayon's seismic monitoring network recorded a volcanic earthquake in the past 24 hours.
"Fair crater glow from the summit could be (also) observed at night," Phivolcs said.
It also warned that people residing close to the declared danger zones to observe precautions due to rockfalls, pyroclastic density currents and ashfall.
"Active stream or river channels and those identified as perennially lahar-prone areas on all sectors of the volcano should also be avoided especially during extreme weather conditions when there is heavy and prolonged rainfall," Phivolcs advised.