Jan. 22 (UPI) -- Philippine authorities raised the volcano alert level on Monday as seismic activity, lava fountains and summit explosions were seen on Mount Mayon.
The mountain on the Philippines' Luzon island, 8,081 feet tall and part of a national park, expelled white smoke, seismologist Renato Solidum said Monday -- an indication that water and lava are mixing.
Philippines Institute of Volcanology and Seismology declared a Level 4 alert, warning of an imminent hazardous eruption. The status is a step below Level 5, indicating a hazardous eruption.
Solidum warned of two possible outcomes -- a series of continuous lava eruptions or a more dangerous pyroclastic flow in which hot lava blocks, pumice, ash, and volcanic gas could move down the mountain. He added that the current eruption could be a "smaller version" of 2001 eruptions at Mount Mayon, which included pyroclastic flow.
An evacuated danger zone was extended to nearly five miles earlier this month.
"The public is reminded to observe the danger zone, not to panic but in essence just be ready. Prepare either gas masks, handkerchiefs or clothes to prevent inhalation of fine ash," said Solidum.
The Albay provincial government canceled all school classes and appealed for supplies of food and face masks from the Philippines' disaster relief agency. Albay Gov. Al Francis Bichara said the volcano destroyed crops in several communities but there have been no reports of illnesses among residents.
Bichara noted, "The eruption is not over yet. Just like we experienced a long time ago, it might extend up to a month."
The country's National Disaster Risk Reduction and Management Council reported that 27,730 people have been evacuated from the danger zone, and are in evacuation centers or staying with family. The airport in Albay's capital city was closed Monday.