The Philippine Institute of Volcanology and Seismology (PHIVOLCS) on Saturday released thermal camera footage of a minor phreatic eruption at Taal Volcano that occurred shortly after midnight.

According to PHIVOLCS, the event took place at 12:16 a.m. at the volcano’s main crater.

“This event generated plumes that rose 300 meters above the crater as recorded by the Main Crater (VTMC) and Daang Kastila (VTDK) thermal cameras,” the agency said in an online post accompanying the sped-up footage.

PHIVOLCS said the eruption was phreatic in nature, or steam-driven, typically caused by the heating of groundwater without the direct involvement of new magma.

Alert Level 1 remains in effect over Taal Volcano, indicating low-level unrest. Authorities continue to monitor the volcano for any signs of increased activity.