Cris Deolata, of the Philippine Institute of Volcanology and Seismology (Phivolcs), said five fissures on the volcano’s northwest and eastern slopes facing Bulusan and Irosin towns have become evident as they now emit steam.
He said the Irosin barangays of Cogon and Patag face the highest threat once Bulusan’s unrest worsens since they are situated near one of the volcano’s lahar channels.
In a bulletin, Phivolcs said two high-frequency volcanic quakes were recorded during the past 24-hour observation period.
There were also "weak" steam emissions from the volcano’s active summit vent and fissure on the western slope, it added.
The institute warned villagers against venturing into the four-kilometer permanent danger zone, particularly near gullies leading to the middle and upper slopes, since sudden explosions and lahar flows may occur.
Health Secretary Francisco Duque said his department has sent medicines, surgical masks and nebulizers for the ashfall-affected Sorsogon folk.
He said measures are in place to protect the villagers from the hazardous sulfuric content of the volcanic ash which, in inhaled, could lead to pulmonary and respiratory ailments and eye irritation.
Alert level 2 is still maintained at Bulusan, but Arnel Capili, Bicol director of the Office of Civil Defense, said they are ready with contingency plans should the situation deteriorates. — With James Mananghaya