Philippines raises volcano alert to 3 after summit collapses on Mayon Volcano

June 8 (UPI) -- The collapse of its summit dome and repeated rockfall events have led Filipino volcano officials to raise the alert level on the Mayon Volcano on Thursday to Level 3.

The Manila-based Philippine Institute of Volcanology and Seismology said there was an "increased tendency towards a hazardous eruption" after the dome collapse. That generated an increasing number and volume of rockfall events.

The institute said it counted 267 rockfall events and two volcanic earthquakes from Monday to Thursday compared to 54 rockfall events from June 1 to 4.

"This means that Mayon is exhibiting magmatic eruption of a summit lava dome, with increased chances of lava flows and hazardous pyroclastic density currents affecting the upper to middle slopes of the volcano and of potential explosive activity within weeks or even days," the institute, known as Phivolcs, said.

Toto Bacolcol, Phivolcs' officer-in-charge, told CNN Philippines that the public should not enter the area because of threats of possible "a pyroclastic density current, lava flows, rock falls, and other volcanic hazards."

"Within 24 hours, we recorded 94 rockfall events and then may [there were] two volcanic events between June 5 to 8," Bacolcol said.

The volcano has not had a steam-driven or phreatic eruption since January 2018. The Philippines is part of the so-called "Ring of Fire" in the Pacific Ocean where most earthquakes and volcanic eruptions occur.