Jan. 23 (UPI) -- Philippine officials cut off electricity and water supplies inside what they consider the "danger zone" around the Mount Mayon volcano -- an effort to keep people away from what could be a devastating eruption.
Residents began evacuating on Jan. 13 after ash eruptions first started, prompting more than 1,500 families to leave the cities of Camalig, Guinobatan and Malilipot.
By Tuesday, tens of thousands had evacuated, officials said. Many were moved to a number of evacuation centers across Albay province.
Flights in and out of the area were also canceled, as well as at-risk schools.
Scientists are not sure how powerful the eruption on Mayon could be, but historical data shows a destructive explosion is possible -- perhaps on the level of a 1984 eruption that covered the surrounding areas with heavy ash and set off volcanic earthquakes.
An eruption of ash, gases and lava on Monday led authorities to declare a Level 4 alert as ashes swept toward nearby towns. The longest lava fountain was reported Sunday morning and lasted for about 30 minutes.
Even with the ongoing activity at the mountain, authorities have not yet raised the alert to Level 5, the highest warning, because movements have so far been intermittent and accurately predicting volcanic eruptions is largely an inexact science.
Paul Alanis, a science research specialist at the Philippine Institute of Volcanology and Seismology, said the Level 4 alert suggests "hazardous eruption is imminent" and could occur within the next few hours or days.