MANILA, Philippines (UPDATE) - Five people were killed and seven were injured when MayonVolcano spewed ash, called a phreatic eruption, reaching 500 meters above its crater on Tuesday morning, the National Disaster Risk Reduction and Management Council reported.
In an advisory, Philippine Institute of Volcanology and Seismology (Phivolcs) said the Mayon Volcano produced a small phreatic event at 8 a.m. and lasted about 73 seconds.
"The gray to brown clouds reached 500 meters above the summit and drifted west southwest.
No volcanic earthquake was detected within the past 24-hour observation period," the agency said. It added that there is no indication of intensification of volcanic activity.
Tour guide Kenneth Jesalva, who climbed up the volcano with seven others on Monday, said in a television interview that three foreign tourists and a tour guide were killed due to the ash ejection.
Still, Phivolcs is maintaining an Alert Level 0 status which means that no volcanic eruption is imminent.
"It is strongly advised that the public refrain from entering the 6- kilometer radius Permanent Danger Zone (PDZ) due to the threat of sudden steam-driven eruptions and rock falls from the upper and middle slopes of the volcano," the agency said in its advisory.
'Shallow' blowup
Phivolcs Director Renato Solidum, Jr. said that the recent activity of the volcano in Albay Bicol is still considered "normal" as the what is considered a phreatic or "shallow" explosion only involves giving off steam, water, volcanic rocks and ashes, but without magma.
"What happened to Mayon Volcano this morning is essentially a hydrothermal or steamed driven explosion," Solidum said.
He explained that the agency maintains the crater's condition to be at Alert Level Zero, as it is "a normal process" in any volcano.
Nearby residents within the danger zone, however, should still be warned even when the situation requires no immediate evacuation, he said.
"There is not much pressure and there is no new magma yet ... but once that steam is hot, there can be pressure and will have shallow explosion," Solidum said.
The official added that the eruption only originated from the crater and what it gave off was "old ash" brought by the opening's steam.
The agency, however, could not squarely determine whether the minor eruption this morning would be followed by another.
"In previous eruptions of Mayon, sometimes another ash explosion would happen but the interval would not be very regular so we don't know what would happen. - with Camille Diola