LEGAZPI CITY -- At least eight volcanic earthquakes rocked Mount Bulusan in Sorosgon, signifying that the volcano continues to show signs of restiveness, the Philippine Institute of Volcanolgy and Seismology (Phivolcs) said Wednesday.

Phivolcs-Bicol resident volcanologist Ed Laguerta said the quakes and the swelling of the volcano’s edifice are signs that pressure is building up in the volcano’s vent.

Aside from eight volcanic quakes, Phivolcs instruments recorded for the past 24-hour observation period slight inflationary trend at the volcano’s edifice during the precise leveling surveys.

Alert Level 1 (abnormal) remains hoisted over the volcano.

Laguerta warned the public to keep off the four-kilometer permanent danger zone due to the possibility of sudden and hazardous steam-driven or phreatic eruptions.

The Phivolcs also advised pilots to avoid flying close to the volcano’s summit as ash from any sudden phreatic eruption can be dangerous to aircraft.

It also warned residents living within valleys and along river channels around the volcano of possible flooding and lahar flows in the event of heavy and prolonged rains. (PNA)