A weak explosion was reported at Mt. Pinatubo in the Philippines on Tuesday, producing a plume, according to the Philippine Institute of Volcanology and Seismology (PHIVOLCS).
The seismic and infrasound signals are not typical of known volcanic processes and are being evaluated together with other potential sources, including aircraft activity, ordnance disposal and others, according to PHIVOLCS. There has also been very low seismic activity in recent days and magmatic activity has been discounted.
PHIVOLCS cautioned the public against venturing in the vicinities of Mt. Pinatubo in the meantime until the source of the explosion has been determined.