The Philippine Institute of Volcanology and Seismology (Phivolcs) raised the alert level of Mayon Volcano to three after "a moderately explosive eruption" was recorded on Friday.

The eruption that occurred at 11:53 am sent "a dense, rapidly ascending and billowing ash plume 3,000 meters above the summit crater".

Phivolcs said "the plume was dispersed to the west-southwest by moderate winds and ashfall is expected to fall in the communities of Daraga, Camalig, Guinobatan and adjacent municipalities of Albay."

Phivolcs said Alert Level 3 "means that Mayon is in a new phase of magmatic eruption, with increased chances of lava flows and hazardous PDCs or uson affecting the upper to middle slopes of the volcano in the immediate days to weeks".

"It is therefore recommended that the 6-km radius Permanent Danger Zone (PDZ) be evacuated due to the danger of PDCs, lava flows, rockfalls and other volcanic hazards," it stated.

"Increased vigilance against pyroclastic density currents, lahars and sediment-laden stream flows along channels draining the edifice is also advised," Phivolcs added.

Pilots are also advised to avoid flying close to the volcano’s summit as ash from any sudden eruption can be hazardous to aircraft.

"Based on the current prevailing wind pattern, ash fall events may most likely occur on the south side of the volcano," said Phivolcs. Robina Asido/PHS