MANILA, Feb. 21 -- The Philippine Institute of Volcanology and Seismology (Phivolcs) urged the public on Friday to increase vigilance against possible lahar from Mayon Volcano.

In an advisory, the Phivolcs said that based on the weather bureau's forecast, the shear line could cause continued potentially high-volume rainfall across the Bicol Region.

Further, heavy to intense rainfall is expected over the Albay Province in the coming days.

This could generate volcanic sediment flows or lahar, muddy streamflows or muddy run-off in rivers and drainage areas, the Phivolcs said.

It added prolonged and heavy rainfall may also generate post-eruption lahars on major channels draining Mayon Volcano by incorporating loose material from remnant p...