MANILA, Philippines - The Philippine Institute of Volcanology and Seismology (Phivolcs) on Monday night placed Mayon Volcano on alert level 3 due to a "noticeable escalation of unrest."
In its 10 p.m. bulletin, Phivolcs said the alert status means that the volcano is showing relatively high unrest and that magma is at the crater.
Hazardous eruption is also possible within weeks, the agency warned.
Philvocs said in its latest update on Tuesday morning that it recorded 32 volcanic earthquakes and 72 rock fall events in the past 24 hours.
Intensity III (bright) crater glow was also seen last night, although rain clouds prevented visual observation of the crater during the day.
Phivolcs said the rolling incandescent rockfall within the uppermost reaches of the Bonga Gully on Monday night indicates that the summit lava dome is breaching the crater in its southeastern side.
Sulfur dioxide flux was measured at an average of 611 tonnes per day on September 2 while ground deformation data showed inflationary changes in the volcano's edifice.
"All the above data indicate that the volcano is exhibiting relatively high unrest due to the movement of potentially eruptible magma," Phivolcs said.
The agency recommended the enforcement of the six-kilometer radius Permanent Danger Zone around the volcano and the seven-kilometer Extended Danger Zone on the southeastern flank due to the danger of rockfalls, landslides and sudden explosions or dome collapse that may generate hazardous volcanic flows.