MANILA, Philippines – The Philippine Institute of Volcanology and Seismology (Phivolcs) recorded Sunday increased seismic activity at Bulusan Volcano in Sorsogon province, 24 hours after the active volcano spewed a 600-meter ash column and grayish steam last Saturday.

State volcanologists noted that at least 10 volcanic earthquakes and four explosion-type events have been documented subsequent to the emission of ash and steam at 8 a.m. on Saturday.

“After the ash ejection (last Saturday), steaming activity was characterized by strong emission of white steam column that reached a maximum height of 200 meters above the crater rim,” Phivolcs said.

Since 2 p.m. on Saturday, visual monitoring of the volcano's other activities were being obscured by thick clouds covering the volcano's summit.

Phivolcs maintains the status of Bulusan Volcano under Alert Level 1 (rendering abnormal activity) due to its current activity that may lead to more steam and ash ejections in the coming days.

It reminded the public not to enter the four-kilometer permanent danger zone from the volcano.

People residing near the valleys and streams were also advised to be “extra alert” against sediment-laden stream flows in the event of heavy rains.

Bulusan Volcano is considered the 4th most active volcano in the country, after mounts Mayon, Taal, and Pinatubo. It has erupted 15 times since 1886.

Since the volcano showed intermittent signs of ash explosions and seismic activity in 2007, Phivolcs reported activity at Bulusan only last Saturday.