The Bulusan Volcano had another phreatic eruption or steam-driven explosion early Sunday morning, June 12, according to the Philippine Institute of Volcanology and Seismology (Phivolcs).

In its advisory, the Phivolcs said the eruption was detected at 3:36 a.m., saying it lasted 18 minutes per the seismic record.

The eruption plume was not visible in camera monitors, it added.

With this, the Phivolcs reminded the public that Alert Level 1 remains over Bulusan Volcano.

“Local government units and the public are reminded that entry into the 4-kilometer radius Permanent Danger Zone (PDZ) must be strictly prohibited and that vigilance in the 2-kilometer Extended Danger Zone (EDZ) on the southeast sector must be exercised due to the increased possibilities of sudden and hazardous phreatic eruption,” it noted.

The Phivolcs also said the Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit, noting that the ash from any sudden phreatic eruption can be hazardous to aircraft.

“People living within valleys and along river/stream channels especially on the southeast, southwest and northwest sector of the edifice should be vigilant against sediment-laden stream flows and lahars in the event of heavy and prolonged rainfall should phreatic eruption occur,” it said.

On June 5, thick smoke billowed from Bulusan Volcano after a phreatic eruption. It was then placed by Phivolcs under Alert Level 1.